diff --git a/src/Compilers/CSharp/Portable/Binder/Binder_Constraints.cs b/src/Compilers/CSharp/Portable/Binder/Binder_Constraints.cs
index 01e38f749c160..36c970f15990a 100644
--- a/src/Compilers/CSharp/Portable/Binder/Binder_Constraints.cs
+++ b/src/Compilers/CSharp/Portable/Binder/Binder_Constraints.cs
@@ -411,9 +411,9 @@ private static void CheckConstraintTypeVisibility(
                 diagnostics.Add(ErrorCode.ERR_BadVisBound, location, containingSymbol, constraintType.Type);
             }
 
-            if (constraintType.Type.IsFileTypeOrUsesFileTypes())
+            if (constraintType.Type.HasFileLocalTypes())
             {
-                // if the containing symbol of the constraint is a member, we need to ensure the nearest containing type is a file type.
+                // if the containing symbol of the constraint is a member, we need to ensure the nearest containing type is a file-local type.
                 var possibleFileType = containingSymbol switch
                 {
                     TypeSymbol typeSymbol => typeSymbol,
@@ -422,7 +422,7 @@ private static void CheckConstraintTypeVisibility(
                     _ => throw ExceptionUtilities.UnexpectedValue(containingSymbol)
                 };
                 Debug.Assert(possibleFileType?.IsDefinition != false);
-                if (possibleFileType?.IsFileTypeOrUsesFileTypes() == false)
+                if (possibleFileType?.HasFileLocalTypes() == false)
                 {
                     diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, location, constraintType.Type, containingSymbol);
                 }
diff --git a/src/Compilers/CSharp/Portable/Binder/Binder_Lookup.cs b/src/Compilers/CSharp/Portable/Binder/Binder_Lookup.cs
index 47bd4d832fccd..f6b33f84e5770 100644
--- a/src/Compilers/CSharp/Portable/Binder/Binder_Lookup.cs
+++ b/src/Compilers/CSharp/Portable/Binder/Binder_Lookup.cs
@@ -1308,14 +1308,14 @@ internal static ImmutableArray<Symbol> GetCandidateMembers(NamespaceOrTypeSymbol
 
         private bool IsInScopeOfAssociatedSyntaxTree(Symbol symbol)
         {
-            while (symbol is not null and not SourceMemberContainerTypeSymbol { IsFile: true })
+            while (symbol is not null and not SourceMemberContainerTypeSymbol { IsFileLocal: true })
             {
                 symbol = symbol.ContainingType;
             }
 
             if (symbol is null)
             {
-                // the passed-in symbol was not contained in a file type.
+                // the passed-in symbol was not contained in a file-local type.
                 return true;
             }
 
diff --git a/src/Compilers/CSharp/Portable/Binder/Binder_Symbols.cs b/src/Compilers/CSharp/Portable/Binder/Binder_Symbols.cs
index ee5c62da9ec38..72fab753cff6b 100644
--- a/src/Compilers/CSharp/Portable/Binder/Binder_Symbols.cs
+++ b/src/Compilers/CSharp/Portable/Binder/Binder_Symbols.cs
@@ -1818,7 +1818,7 @@ Symbol resultSymbol(
 
                         if (best.IsFromFile && !secondBest.IsFromFile)
                         {
-                            // a lookup of a file type is "better" than a lookup of a non-file type; no need to further diagnose
+                            // a lookup of a file-local type is "better" than a lookup of a non-file-local type; no need to further diagnose
                             // https://github.com/dotnet/roslyn/issues/62331
                             // some "single symbol" diagnostics are missed here for similar reasons
                             // that make us miss diagnostics when reporting WRN_SameFullNameThisAggAgg.
@@ -2300,7 +2300,7 @@ private BestSymbolInfo GetBestSymbolInfo(ArrayBuilder<Symbol> symbols, out BestS
 
         private static BestSymbolLocation GetLocation(CSharpCompilation compilation, Symbol symbol)
         {
-            if (symbol is SourceMemberContainerTypeSymbol { IsFile: true })
+            if (symbol is SourceMemberContainerTypeSymbol { IsFileLocal: true })
             {
                 return BestSymbolLocation.FromFile;
             }
diff --git a/src/Compilers/CSharp/Portable/CSharpResources.resx b/src/Compilers/CSharp/Portable/CSharpResources.resx
index 71812dab8308f..69bfcdca2d78c 100644
--- a/src/Compilers/CSharp/Portable/CSharpResources.resx
+++ b/src/Compilers/CSharp/Portable/CSharpResources.resx
@@ -7125,19 +7125,19 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
     <value>'{2}' cannot satisfy the 'new()' constraint on parameter '{1}' in the generic type or or method '{0}' because '{2}' has required members.</value>
   </data>
   <data name="ERR_FileTypeDisallowedInSignature" xml:space="preserve">
-    <value>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</value>
+    <value>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</value>
   </data>
   <data name="ERR_FileTypeNoExplicitAccessibility" xml:space="preserve">
-    <value>File type '{0}' cannot use accessibility modifiers.</value>
+    <value>File-local type '{0}' cannot use accessibility modifiers.</value>
   </data>
   <data name="ERR_FileTypeBase" xml:space="preserve">
-    <value>File type '{0}' cannot be used as a base type of non-file type '{1}'.</value>
+    <value>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</value>
   </data>
   <data name="ERR_FileTypeNested" xml:space="preserve">
-    <value>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</value>
+    <value>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</value>
   </data>
   <data name="ERR_GlobalUsingStaticFileType" xml:space="preserve">
-    <value>File type '{0}' cannot be used in a 'global using static' directive.</value>
+    <value>File-local type '{0}' cannot be used in a 'global using static' directive.</value>
   </data>
   <data name="ERR_FileTypeNameDisallowed" xml:space="preserve">
     <value>Types and aliases cannot be named 'file'.</value>
diff --git a/src/Compilers/CSharp/Portable/Symbols/NamedTypeSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/NamedTypeSymbol.cs
index ba0392ec81bbb..7e761e6004936 100644
--- a/src/Compilers/CSharp/Portable/Symbols/NamedTypeSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/NamedTypeSymbol.cs
@@ -497,7 +497,7 @@ public override string MetadataName
         }
 
         /// <summary>
-        /// If this type is a file type, returns the syntax tree where this type is visible. Otherwise, returns null.
+        /// If this type is a file-local type, returns the syntax tree where this type is visible. Otherwise, returns null.
         /// </summary>
         internal abstract SyntaxTree? AssociatedSyntaxTree { get; }
 #nullable disable
diff --git a/src/Compilers/CSharp/Portable/Symbols/PublicModel/NamedTypeSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/PublicModel/NamedTypeSymbol.cs
index 6f09cef0e4714..00c5b7985b11c 100644
--- a/src/Compilers/CSharp/Portable/Symbols/PublicModel/NamedTypeSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/PublicModel/NamedTypeSymbol.cs
@@ -194,7 +194,7 @@ INamedTypeSymbol INamedTypeSymbol.TupleUnderlyingType
 
         bool INamedTypeSymbol.IsSerializable => UnderlyingNamedTypeSymbol.IsSerializable;
 
-        bool INamedTypeSymbol.IsFile => UnderlyingNamedTypeSymbol.AssociatedSyntaxTree is not null;
+        bool INamedTypeSymbol.IsFileLocal => UnderlyingNamedTypeSymbol.AssociatedSyntaxTree is not null;
 
         INamedTypeSymbol INamedTypeSymbol.NativeIntegerUnderlyingType => UnderlyingNamedTypeSymbol.NativeIntegerUnderlyingType.GetPublicSymbol();
 
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceDelegateMethodSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceDelegateMethodSymbol.cs
index 987d3a7e93160..211d1913e0330 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourceDelegateMethodSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourceDelegateMethodSymbol.cs
@@ -96,8 +96,8 @@ internal static void AddDelegateMembers(
                 diagnostics.Add(ErrorCode.ERR_BadVisDelegateReturn, delegateType.Locations[0], delegateType, invoke.ReturnType);
             }
 
-            var delegateTypeIsFile = delegateType.IsFileTypeOrUsesFileTypes();
-            if (!delegateTypeIsFile && invoke.ReturnType.IsFileTypeOrUsesFileTypes())
+            var delegateTypeIsFile = delegateType.HasFileLocalTypes();
+            if (!delegateTypeIsFile && invoke.ReturnType.HasFileLocalTypes())
             {
                 diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, delegateType.Locations[0], invoke.ReturnType, delegateType);
             }
@@ -110,7 +110,7 @@ internal static void AddDelegateMembers(
                     // Inconsistent accessibility: parameter type '{1}' is less accessible than delegate '{0}'
                     diagnostics.Add(ErrorCode.ERR_BadVisDelegateParam, delegateType.Locations[0], delegateType, parameterSymbol.Type);
                 }
-                else if (!delegateTypeIsFile && parameterSymbol.Type.IsFileTypeOrUsesFileTypes())
+                else if (!delegateTypeIsFile && parameterSymbol.Type.HasFileLocalTypes())
                 {
                     diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, delegateType.Locations[0], parameterSymbol.Type, delegateType);
                 }
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberContainerSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberContainerSymbol.cs
index eb9c4c3be96b4..0ba470a975e8d 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberContainerSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberContainerSymbol.cs
@@ -275,7 +275,7 @@ private DeclarationModifiers MakeModifiers(TypeKind typeKind, BindingDiagnosticB
             Symbol containingSymbol = this.ContainingSymbol;
             DeclarationModifiers defaultAccess;
 
-            // note: we give a specific diagnostic when a file type is nested
+            // note: we give a specific diagnostic when a file-local type is nested
             var allowedModifiers = DeclarationModifiers.AccessibilityMask | DeclarationModifiers.File;
 
             if (containingSymbol.Kind == SymbolKind.Namespace)
@@ -826,9 +826,9 @@ internal override ManagedKind GetManagedKind(ref CompoundUseSiteInfo<AssemblySym
 
         internal bool IsNew => HasFlag(DeclarationModifiers.New);
 
-        internal bool IsFile => HasFlag(DeclarationModifiers.File);
+        internal bool IsFileLocal => HasFlag(DeclarationModifiers.File);
 
-        internal sealed override SyntaxTree? AssociatedSyntaxTree => IsFile ? declaration.Declarations[0].Location.SourceTree : null;
+        internal sealed override SyntaxTree? AssociatedSyntaxTree => IsFileLocal ? declaration.Declarations[0].Location.SourceTree : null;
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private bool HasFlag(DeclarationModifiers flag) => (_declModifiers & flag) != 0;
@@ -1744,7 +1744,7 @@ protected void AfterMembersChecks(BindingDiagnosticBag diagnostics)
                 }
             }
 
-            if (IsFile && (object?)ContainingType != null)
+            if (IsFileLocal && (object?)ContainingType != null)
             {
                 diagnostics.Add(ErrorCode.ERR_FileTypeNested, location, this);
             }
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberFieldSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberFieldSymbol.cs
index 791b88c38b64d..ee31d81fceb4a 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberFieldSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberFieldSymbol.cs
@@ -46,7 +46,7 @@ protected sealed override DeclarationModifiers Modifiers
 
         protected void TypeChecks(TypeSymbol type, BindingDiagnosticBag diagnostics)
         {
-            if (type.IsFileTypeOrUsesFileTypes() && !ContainingType.IsFileTypeOrUsesFileTypes())
+            if (type.HasFileLocalTypes() && !ContainingType.HasFileLocalTypes())
             {
                 diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, this.ErrorLocation, type, ContainingType);
             }
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberMethodSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberMethodSymbol.cs
index 225c383d4f001..0f85bdb093238 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberMethodSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberMethodSymbol.cs
@@ -280,19 +280,19 @@ protected void CheckEffectiveAccessibility(TypeWithAnnotations returnType, Immut
 
         protected void CheckFileTypeUsage(TypeWithAnnotations returnType, ImmutableArray<ParameterSymbol> parameters, BindingDiagnosticBag diagnostics)
         {
-            if (ContainingType.IsFileTypeOrUsesFileTypes())
+            if (ContainingType.HasFileLocalTypes())
             {
                 return;
             }
 
-            if (returnType.Type.IsFileTypeOrUsesFileTypes())
+            if (returnType.Type.HasFileLocalTypes())
             {
                 diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, Locations[0], returnType.Type, ContainingType);
             }
 
             foreach (var param in parameters)
             {
-                if (param.Type.IsFileTypeOrUsesFileTypes())
+                if (param.Type.HasFileLocalTypes())
                 {
                     diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, Locations[0], param.Type, ContainingType);
                 }
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamedTypeSymbol_Bases.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamedTypeSymbol_Bases.cs
index 93fe92389fec6..578f93c6c578d 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamedTypeSymbol_Bases.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamedTypeSymbol_Bases.cs
@@ -385,7 +385,7 @@ static bool containsOnlyOblivious(TypeSymbol type)
                     diagnostics.Add(ErrorCode.ERR_BadVisBaseClass, baseTypeLocation, this, baseType);
                 }
 
-                if (baseType.IsFileTypeOrUsesFileTypes() && !this.IsFileTypeOrUsesFileTypes())
+                if (baseType.HasFileLocalTypes() && !this.HasFileLocalTypes())
                 {
                     diagnostics.Add(ErrorCode.ERR_FileTypeBase, baseTypeLocation, baseType, this);
                 }
@@ -402,7 +402,7 @@ static bool containsOnlyOblivious(TypeSymbol type)
                         diagnostics.Add(ErrorCode.ERR_BadVisBaseInterface, interfaceLocations[i], this, i);
                     }
 
-                    if (i.IsFileTypeOrUsesFileTypes() && !this.IsFileTypeOrUsesFileTypes())
+                    if (i.HasFileLocalTypes() && !this.HasFileLocalTypes())
                     {
                         diagnostics.Add(ErrorCode.ERR_FileTypeBase, interfaceLocations[i], i, this);
                     }
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.AliasesAndUsings.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.AliasesAndUsings.cs
index b1098e3ea273f..3c43ab7020c94 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.AliasesAndUsings.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.AliasesAndUsings.cs
@@ -757,7 +757,7 @@ UsingsAndDiagnostics buildUsings(
                                 else
                                 {
                                     var importedType = (NamedTypeSymbol)imported;
-                                    if (usingDirective.GlobalKeyword != default(SyntaxToken) && importedType.IsFileTypeOrUsesFileTypes())
+                                    if (usingDirective.GlobalKeyword != default(SyntaxToken) && importedType.HasFileLocalTypes())
                                     {
                                         diagnostics.Add(ErrorCode.ERR_GlobalUsingStaticFileType, usingDirective.Name.Location, imported);
                                     }
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.cs
index 5bba097c91837..edd2c8d9c133e 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourceNamespaceSymbol.cs
@@ -374,7 +374,7 @@ private static void CheckMembers(NamespaceSymbol @namespace, Dictionary<string,
                     {
                         switch (nts, other)
                         {
-                            case (SourceNamedTypeSymbol left, SourceNamedTypeSymbol right) when isFileTypeInSeparateFileFrom(left, right) || isFileTypeInSeparateFileFrom(right, left):
+                            case (SourceNamedTypeSymbol left, SourceNamedTypeSymbol right) when isFileLocalTypeInSeparateFileFrom(left, right) || isFileLocalTypeInSeparateFileFrom(right, left):
                                 // no error
                                 break;
                             case (SourceNamedTypeSymbol { IsPartial: true }, SourceNamedTypeSymbol { IsPartial: true }):
@@ -400,14 +400,14 @@ private static void CheckMembers(NamespaceSymbol @namespace, Dictionary<string,
                 }
             }
 
-            static bool isFileTypeInSeparateFileFrom(SourceNamedTypeSymbol possibleFileType, SourceNamedTypeSymbol otherSymbol)
+            static bool isFileLocalTypeInSeparateFileFrom(SourceNamedTypeSymbol possibleFileLocalType, SourceNamedTypeSymbol otherSymbol)
             {
-                if (!possibleFileType.IsFile)
+                if (!possibleFileLocalType.IsFileLocal)
                 {
                     return false;
                 }
 
-                var leftTree = possibleFileType.MergedDeclaration.Declarations[0].Location.SourceTree;
+                var leftTree = possibleFileLocalType.MergedDeclaration.Declarations[0].Location.SourceTree;
                 if (otherSymbol.MergedDeclaration.NameLocations.Any((loc, leftTree) => (object)loc.SourceTree == leftTree, leftTree))
                 {
                     return false;
diff --git a/src/Compilers/CSharp/Portable/Symbols/Source/SourcePropertySymbol.cs b/src/Compilers/CSharp/Portable/Symbols/Source/SourcePropertySymbol.cs
index 781b6bac6a5c7..4426258799b56 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Source/SourcePropertySymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Source/SourcePropertySymbol.cs
@@ -451,7 +451,7 @@ private TypeWithAnnotations ComputeType(Binder binder, SyntaxNode syntax, Bindin
                 diagnostics.Add((this.IsIndexer ? ErrorCode.ERR_BadVisIndexerReturn : ErrorCode.ERR_BadVisPropertyType), Location, this, type.Type);
             }
 
-            if (type.Type.IsFileTypeOrUsesFileTypes() && !ContainingType.IsFileTypeOrUsesFileTypes())
+            if (type.Type.HasFileLocalTypes() && !ContainingType.HasFileLocalTypes())
             {
                 diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, Location, type.Type, ContainingType);
             }
@@ -533,7 +533,7 @@ internal override void AfterAddingTypeMembersChecks(ConversionsBase conversions,
                 {
                     diagnostics.Add(ErrorCode.ERR_BadVisIndexerParam, Location, this, param.Type);
                 }
-                else if (param.Type.IsFileTypeOrUsesFileTypes() && !this.ContainingType.IsFileTypeOrUsesFileTypes())
+                else if (param.Type.HasFileLocalTypes() && !this.ContainingType.HasFileLocalTypes())
                 {
                     diagnostics.Add(ErrorCode.ERR_FileTypeDisallowedInSignature, Location, param.Type, this.ContainingType);
                 }
diff --git a/src/Compilers/CSharp/Portable/Symbols/Synthesized/GeneratedNameParser.cs b/src/Compilers/CSharp/Portable/Symbols/Synthesized/GeneratedNameParser.cs
index 55f6d2b85c572..1faeda09dbd5c 100644
--- a/src/Compilers/CSharp/Portable/Symbols/Synthesized/GeneratedNameParser.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/Synthesized/GeneratedNameParser.cs
@@ -172,12 +172,12 @@ internal static bool TryParseAnonymousTypeParameterName(string typeParameterName
             return false;
         }
 
-        // A full metadata name for a generic file type looks like:
+        // A full metadata name for a generic file-local type looks like:
         // <ContainingFile>FN__ClassName`A
         // where 'N' is the syntax tree ordinal, 'A' is the arity,
         // and 'ClassName' is the source name of the type.
         //
-        // The "unmangled" name of a generic file type looks like:
+        // The "unmangled" name of a generic file-local type looks like:
         // <ContainingFile>FN__ClassName
         private static readonly Regex s_fileTypeOrdinalPattern = new Regex(@"<([a-zA-Z_0-9]*)>F(\d)+__", RegexOptions.Compiled);
 
diff --git a/src/Compilers/CSharp/Portable/Symbols/TypeSymbolExtensions.cs b/src/Compilers/CSharp/Portable/Symbols/TypeSymbolExtensions.cs
index c754ed3038577..16f7cd6b8144a 100644
--- a/src/Compilers/CSharp/Portable/Symbols/TypeSymbolExtensions.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/TypeSymbolExtensions.cs
@@ -1361,9 +1361,9 @@ public static bool IsPartial(this TypeSymbol type)
             return type is SourceNamedTypeSymbol { IsPartial: true };
         }
 
-        public static bool IsFileTypeOrUsesFileTypes(this TypeSymbol type)
+        public static bool HasFileLocalTypes(this TypeSymbol type)
         {
-            var foundType = type.VisitType(predicate: (type, _, _) => type is SourceMemberContainerTypeSymbol { IsFile: true }, arg: (object?)null);
+            var foundType = type.VisitType(predicate: (type, _, _) => type is SourceMemberContainerTypeSymbol { IsFileLocal: true }, arg: (object?)null);
             return foundType is not null;
         }
 
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.cs.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.cs.xlf
index a6b62e33cdfaf..7e58ff02580a0 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.cs.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.cs.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.de.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.de.xlf
index ac2a69e0f8fb3..3affc94baac3d 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.de.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.de.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.es.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.es.xlf
index 0f5fa3e1a17c3..8cac02df3fc3e 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.es.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.es.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.fr.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.fr.xlf
index 99a504c03c8db..e44ebe336ed86 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.fr.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.fr.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.it.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.it.xlf
index 1c481b4cde75c..e339116673a1e 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.it.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.it.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ja.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ja.xlf
index c5b80e20dfd6f..e109544a8f9cb 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ja.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ja.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ko.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ko.xlf
index f00c5e27564ca..adb4fec56b30e 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ko.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ko.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.pl.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.pl.xlf
index f5152eea06c8a..36ed6f0d45577 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.pl.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.pl.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.pt-BR.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.pt-BR.xlf
index b4825d1d8710a..702e8b212618e 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.pt-BR.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.pt-BR.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ru.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ru.xlf
index 163f1fdbc972f..c2af4d66a1c1b 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.ru.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.ru.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.tr.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.tr.xlf
index ccb8dd1311727..4d9f80bbddfef 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.tr.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.tr.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hans.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hans.xlf
index a8ea9ff3480d1..5117c46b5cb7f 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hans.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hans.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hant.xlf b/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hant.xlf
index b733798cd83b4..7953331173964 100644
--- a/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hant.xlf
+++ b/src/Compilers/CSharp/Portable/xlf/CSharpResources.zh-Hant.xlf
@@ -588,13 +588,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeBase">
-        <source>File type '{0}' cannot be used as a base type of non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used as a base type of non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used as a base type of non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeDisallowedInSignature">
-        <source>File type '{0}' cannot be used in a member signature in non-file type '{1}'.</source>
-        <target state="new">File type '{0}' cannot be used in a member signature in non-file type '{1}'.</target>
+        <source>File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</source>
+        <target state="new">File-local type '{0}' cannot be used in a member signature in non-file-local type '{1}'.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNameDisallowed">
@@ -603,13 +603,13 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNested">
-        <source>File type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
-        <target state="new">File type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
+        <source>File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</source>
+        <target state="new">File-local type '{0}' must be defined in a top level type; '{0}' is a nested type.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FileTypeNoExplicitAccessibility">
-        <source>File type '{0}' cannot use accessibility modifiers.</source>
-        <target state="new">File type '{0}' cannot use accessibility modifiers.</target>
+        <source>File-local type '{0}' cannot use accessibility modifiers.</source>
+        <target state="new">File-local type '{0}' cannot use accessibility modifiers.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_FixedFieldMustNotBeRef">
@@ -658,8 +658,8 @@
         <note />
       </trans-unit>
       <trans-unit id="ERR_GlobalUsingStaticFileType">
-        <source>File type '{0}' cannot be used in a 'global using static' directive.</source>
-        <target state="new">File type '{0}' cannot be used in a 'global using static' directive.</target>
+        <source>File-local type '{0}' cannot be used in a 'global using static' directive.</source>
+        <target state="new">File-local type '{0}' cannot be used in a 'global using static' directive.</target>
         <note />
       </trans-unit>
       <trans-unit id="ERR_GoToBackwardJumpOverUsingVar">
diff --git a/src/Compilers/CSharp/Test/Symbol/Symbols/Source/FileModifierTests.cs b/src/Compilers/CSharp/Test/Symbol/Symbols/Source/FileModifierTests.cs
index dd70659524ee9..b27f17ef1d8f8 100644
--- a/src/Compilers/CSharp/Test/Symbol/Symbols/Source/FileModifierTests.cs
+++ b/src/Compilers/CSharp/Test/Symbol/Symbols/Source/FileModifierTests.cs
@@ -47,13 +47,13 @@ file class C { }
             // (3,16): error CS8936: Feature 'file types' is not available in C# 10.0. Please use language version 11.0 or greater.
             //     file class C { }
             Diagnostic(ErrorCode.ERR_FeatureNotAvailableInVersion10, "C").WithArguments("file types", "11.0").WithLocation(3, 16),
-            // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C { }
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16));
 
         comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C { }
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16));
     }
@@ -83,11 +83,11 @@ void verify()
         {
             var outer = comp.GetMember<NamedTypeSymbol>("Outer");
             Assert.Equal(Accessibility.Internal, outer.DeclaredAccessibility);
-            Assert.True(((SourceMemberContainerTypeSymbol)outer).IsFile);
+            Assert.True(((SourceMemberContainerTypeSymbol)outer).IsFileLocal);
 
             var classC = comp.GetMember<NamedTypeSymbol>("Outer.C");
             Assert.Equal(Accessibility.Private, classC.DeclaredAccessibility);
-            Assert.False(((SourceMemberContainerTypeSymbol)classC).IsFile);
+            Assert.False(((SourceMemberContainerTypeSymbol)classC).IsFileLocal);
         }
     }
 
@@ -109,13 +109,13 @@ file class C { }
             // (3,16): error CS8936: Feature 'file types' is not available in C# 10.0. Please use language version 11.0 or greater.
             //     file class C { }
             Diagnostic(ErrorCode.ERR_FeatureNotAvailableInVersion10, "C").WithArguments("file types", "11.0").WithLocation(3, 16),
-            // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C { }
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16));
 
         comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C { }
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16));
     }
@@ -137,7 +137,7 @@ void M(Outer.C c) { } // 1
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (8,10): error CS9051: File type 'Outer.C' cannot be used in a member signature in non-file type 'D'.
+            // (8,10): error CS9051: File-local type 'Outer.C' cannot be used in a member signature in non-file-local type 'D'.
             //     void M(Outer.C c) { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M").WithArguments("Outer.C", "D").WithLocation(8, 10));
     }
@@ -396,7 +396,7 @@ static void Main()
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (10,12): error CS9051: File type 'E' cannot be used in a member signature in non-file type 'Attr'.
+            // (10,12): error CS9051: File-local type 'E' cannot be used in a member signature in non-file-local type 'Attr'.
             //     public Attr(E e) { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "Attr").WithArguments("E", "Attr").WithLocation(10, 12));
     }
@@ -713,8 +713,8 @@ void validateSymbols(ModuleSymbol module)
     [InlineData("", "file", "C", "<>F1__C")]
     public void Duplication_01(string firstFileModifier, string secondFileModifier, string firstMetadataName, string secondMetadataName)
     {
-        // A file type is allowed to have the same name as a non-file type from a different file.
-        // When both a file type and non-file type with the same name are in scope, the file type is preferred, since it's "more local".
+        // A file-local type is allowed to have the same name as a non-file-local type from a different file.
+        // When both a file-local type and non-file-local type with the same name are in scope, the file-local type is preferred, since it's "more local".
         var source1 = $$"""
             using System;
 
@@ -896,7 +896,7 @@ static void Main()
         Assert.Equal(2, cs.Length);
 
         var c0 = cs[0];
-        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFile: false });
+        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFileLocal: false });
 
         var syntaxReferences = c0.DeclaringSyntaxReferences;
         Assert.Equal(2, syntaxReferences.Length);
@@ -904,7 +904,7 @@ static void Main()
         Assert.Equal(comp.SyntaxTrees[1], syntaxReferences[1].SyntaxTree);
 
         var c1 = cs[1];
-        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         Assert.Equal(comp.SyntaxTrees[2], c1.DeclaringSyntaxReferences.Single().SyntaxTree);
 
         var tree = comp.SyntaxTrees[2];
@@ -962,11 +962,11 @@ static void Main()
         Assert.Equal(2, cs.Length);
 
         var c0 = cs[0];
-        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFile: false });
+        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFileLocal: false });
         Assert.Equal(comp.SyntaxTrees[0], c0.DeclaringSyntaxReferences.Single().SyntaxTree);
 
         var c1 = cs[1];
-        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
 
         var syntaxReferences = c1.DeclaringSyntaxReferences;
         Assert.Equal(2, syntaxReferences.Length);
@@ -1024,11 +1024,11 @@ static void Main()
         Assert.Equal(2, cs.Length);
 
         var c0 = cs[0];
-        Assert.Equal(firstClassIsFile, ((SourceMemberContainerTypeSymbol)c0).IsFile);
+        Assert.Equal(firstClassIsFile, ((SourceMemberContainerTypeSymbol)c0).IsFileLocal);
         Assert.Equal(comp.SyntaxTrees[0], c0.DeclaringSyntaxReferences.Single().SyntaxTree);
 
         var c1 = cs[1];
-        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         Assert.Equal(comp.SyntaxTrees[1], c1.DeclaringSyntaxReferences.Single().SyntaxTree);
 
         var tree = comp.SyntaxTrees[1];
@@ -1082,14 +1082,14 @@ public static void M()
         Assert.Equal(2, cs.Length);
 
         var c0 = cs[0];
-        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFile: false });
+        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFileLocal: false });
         var syntaxReferences = c0.DeclaringSyntaxReferences;
         Assert.Equal(2, syntaxReferences.Length);
         Assert.Equal(comp.SyntaxTrees[0], syntaxReferences[0].SyntaxTree);
         Assert.Equal(comp.SyntaxTrees[1], syntaxReferences[1].SyntaxTree);
 
         var c1 = cs[1];
-        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         Assert.Equal(comp.SyntaxTrees[1], c1.DeclaringSyntaxReferences.Single().SyntaxTree);
 
 
@@ -1103,7 +1103,7 @@ public static void M()
             Diagnostic(ErrorCode.ERR_MissingPartial, "C").WithArguments("C").WithLocation(8, 12));
 
         var c = comp.GetMember("C");
-        Assert.True(c is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         syntaxReferences = c.DeclaringSyntaxReferences;
         Assert.Equal(3, syntaxReferences.Length);
         Assert.Equal(comp.SyntaxTrees[0], syntaxReferences[0].SyntaxTree);
@@ -1153,11 +1153,11 @@ file class C
         Assert.Equal(2, cs.Length);
 
         var c0 = cs[0];
-        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         Assert.Equal(comp.SyntaxTrees[0], c0.DeclaringSyntaxReferences.Single().SyntaxTree);
 
         var c1 = cs[1];
-        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         var syntaxReferences = c1.DeclaringSyntaxReferences;
         Assert.Equal(2, syntaxReferences.Length);
         Assert.Equal(comp.SyntaxTrees[1], syntaxReferences[0].SyntaxTree);
@@ -1174,14 +1174,14 @@ file class C
         Assert.Equal(2, cs.Length);
 
         c0 = cs[0];
-        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c0 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         syntaxReferences = c0.DeclaringSyntaxReferences;
         Assert.Equal(2, syntaxReferences.Length);
         Assert.Equal(comp.SyntaxTrees[0], syntaxReferences[0].SyntaxTree);
         Assert.Equal(comp.SyntaxTrees[0], syntaxReferences[1].SyntaxTree);
 
         c1 = cs[1];
-        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFile: true });
+        Assert.True(c1 is SourceMemberContainerTypeSymbol { IsFileLocal: true });
         Assert.Equal(comp.SyntaxTrees[1], c1.DeclaringSyntaxReferences.Single().SyntaxTree);
     }
 
@@ -1220,19 +1220,19 @@ public static void M() { }
 
         var compilation = CreateCompilation(new[] { source1, source2, source3 });
         compilation.VerifyDiagnostics(
-            // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16),
-            // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16));
 
         var classOuter = compilation.GetMember<NamedTypeSymbol>("Outer");
         var cs = classOuter.GetMembers("C");
         Assert.Equal(3, cs.Length);
-        Assert.True(cs[0] is SourceMemberContainerTypeSymbol { IsFile: true });
-        Assert.True(cs[1] is SourceMemberContainerTypeSymbol { IsFile: true });
-        Assert.True(cs[2] is SourceMemberContainerTypeSymbol { IsFile: false });
+        Assert.True(cs[0] is SourceMemberContainerTypeSymbol { IsFileLocal: true });
+        Assert.True(cs[1] is SourceMemberContainerTypeSymbol { IsFileLocal: true });
+        Assert.True(cs[2] is SourceMemberContainerTypeSymbol { IsFileLocal: false });
     }
 
     [Fact]
@@ -1274,9 +1274,9 @@ public static void M() { }
         var namespaceNS = compilation.GetMember<NamespaceSymbol>("NS");
         var cs = namespaceNS.GetMembers("C");
         Assert.Equal(3, cs.Length);
-        Assert.True(cs[0] is SourceMemberContainerTypeSymbol { IsFile: true });
-        Assert.True(cs[1] is SourceMemberContainerTypeSymbol { IsFile: true });
-        Assert.True(cs[2] is SourceMemberContainerTypeSymbol { IsFile: false });
+        Assert.True(cs[0] is SourceMemberContainerTypeSymbol { IsFileLocal: true });
+        Assert.True(cs[1] is SourceMemberContainerTypeSymbol { IsFileLocal: true });
+        Assert.True(cs[2] is SourceMemberContainerTypeSymbol { IsFileLocal: false });
     }
 
     [Theory]
@@ -1579,10 +1579,10 @@ private void M2(C c) { } // 2
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,17): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (7,17): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public void M1(C c) { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M1").WithArguments("C", "D").WithLocation(7, 17),
-            // (8,18): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (8,18): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     private void M2(C c) { } // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M2").WithArguments("C", "D").WithLocation(8, 18));
     }
@@ -1604,10 +1604,10 @@ class D
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,14): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (7,14): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public C M1() => new C(); // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M1").WithArguments("C", "D").WithLocation(7, 14),
-            // (8,15): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (8,15): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     private C M2() => new C(); // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M2").WithArguments("C", "D").WithLocation(8, 15));
     }
@@ -1632,19 +1632,19 @@ public class E
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (8,7): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'E'.
+            // (8,7): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'E'.
             //     C field; // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "field").WithArguments("C", "E").WithLocation(8, 7),
             // (8,7): warning CS0169: The field 'E.field' is never used
             //     C field; // 1
             Diagnostic(ErrorCode.WRN_UnreferencedField, "field").WithArguments("E.field").WithLocation(8, 7),
-            // (9,7): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'E'.
+            // (9,7): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'E'.
             //     C property { get; set; } // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "property").WithArguments("C", "E").WithLocation(9, 7),
-            // (10,12): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'E'.
+            // (10,12): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'E'.
             //     object this[C c] { get => c; set { } } // 3
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "this").WithArguments("C", "E").WithLocation(10, 12),
-            // (11,13): error CS9051: File type 'D' cannot be used in a member signature in non-file type 'E'.
+            // (11,13): error CS9051: File-local type 'D' cannot be used in a member signature in non-file-local type 'E'.
             //     event D @event; // 4
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "@event").WithArguments("D", "E").WithLocation(11, 13),
             // (11,13): warning CS0067: The event 'E.event' is never used
@@ -1673,19 +1673,19 @@ public class E
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (9,13): error CS9051: File type 'C.Inner' cannot be used in a member signature in non-file type 'E'.
+            // (9,13): error CS9051: File-local type 'C.Inner' cannot be used in a member signature in non-file-local type 'E'.
             //     C.Inner field; // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "field").WithArguments("C.Inner", "E").WithLocation(9, 13),
             // (9,13): warning CS0169: The field 'E.field' is never used
             //     C.Inner field; // 1
             Diagnostic(ErrorCode.WRN_UnreferencedField, "field").WithArguments("E.field").WithLocation(9, 13),
-            // (10,13): error CS9051: File type 'C.Inner' cannot be used in a member signature in non-file type 'E'.
+            // (10,13): error CS9051: File-local type 'C.Inner' cannot be used in a member signature in non-file-local type 'E'.
             //     C.Inner property { get; set; } // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "property").WithArguments("C.Inner", "E").WithLocation(10, 13),
-            // (11,12): error CS9051: File type 'C.Inner' cannot be used in a member signature in non-file type 'E'.
+            // (11,12): error CS9051: File-local type 'C.Inner' cannot be used in a member signature in non-file-local type 'E'.
             //     object this[C.Inner inner] { get => inner; set { } } // 3
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "this").WithArguments("C.Inner", "E").WithLocation(11, 12),
-            // (12,27): error CS9051: File type 'C.InnerDelegate' cannot be used in a member signature in non-file type 'E'.
+            // (12,27): error CS9051: File-local type 'C.InnerDelegate' cannot be used in a member signature in non-file-local type 'E'.
             //     event C.InnerDelegate @event; // 4
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "@event").WithArguments("C.InnerDelegate", "E").WithLocation(12, 27),
             // (12,27): warning CS0067: The event 'E.event' is never used
@@ -1730,16 +1730,16 @@ public class Inner
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (24,17): error CS9051: File type 'C.Inner' cannot be used in a member signature in non-file type 'E.Inner'.
+            // (24,17): error CS9051: File-local type 'C.Inner' cannot be used in a member signature in non-file-local type 'E.Inner'.
             //         C.Inner field; // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "field").WithArguments("C.Inner", "E.Inner").WithLocation(24, 17),
-            // (25,17): error CS9051: File type 'C.Inner' cannot be used in a member signature in non-file type 'E.Inner'.
+            // (25,17): error CS9051: File-local type 'C.Inner' cannot be used in a member signature in non-file-local type 'E.Inner'.
             //         C.Inner property { get; set; } // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "property").WithArguments("C.Inner", "E.Inner").WithLocation(25, 17),
-            // (26,16): error CS9051: File type 'C.Inner' cannot be used in a member signature in non-file type 'E.Inner'.
+            // (26,16): error CS9051: File-local type 'C.Inner' cannot be used in a member signature in non-file-local type 'E.Inner'.
             //         object this[C.Inner inner] { get => inner; set { } } // 3
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "this").WithArguments("C.Inner", "E.Inner").WithLocation(26, 16),
-            // (27,31): error CS9051: File type 'C.InnerDelegate' cannot be used in a member signature in non-file type 'E.Inner'.
+            // (27,31): error CS9051: File-local type 'C.InnerDelegate' cannot be used in a member signature in non-file-local type 'E.Inner'.
             //         event C.InnerDelegate @event; // 4
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "@event").WithArguments("C.InnerDelegate", "E.Inner").WithLocation(27, 31));
     }
@@ -1758,10 +1758,10 @@ file class C
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (5,15): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'Del1'.
+            // (5,15): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'Del1'.
             // delegate void Del1(C c); // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "Del1").WithArguments("C", "Del1").WithLocation(5, 15),
-            // (6,12): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'Del2'.
+            // (6,12): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'Del2'.
             // delegate C Del2(); // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "Del2").WithArguments("C", "Del2").WithLocation(6, 12));
     }
@@ -1783,10 +1783,10 @@ class D
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,30): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (7,30): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public static D operator +(D d, C c) => d; // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "+").WithArguments("C", "D").WithLocation(7, 30),
-            // (8,30): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (8,30): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public static C operator -(D d1, D d2) => new C(); // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "-").WithArguments("C", "D").WithLocation(8, 30));
     }
@@ -1807,7 +1807,7 @@ public D(C c) { } // 1
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,12): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (7,12): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public D(C c) { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "D").WithArguments("C", "D").WithLocation(7, 12));
     }
@@ -1828,13 +1828,13 @@ class D
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,14): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (7,14): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public C M(C c1, C c2) => c1; // 1, 2, 3
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M").WithArguments("C", "D").WithLocation(7, 14),
-            // (7,14): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (7,14): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public C M(C c1, C c2) => c1; // 1, 2, 3
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M").WithArguments("C", "D").WithLocation(7, 14),
-            // (7,14): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D'.
+            // (7,14): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D'.
             //     public C M(C c1, C c2) => c1; // 1, 2, 3
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M").WithArguments("C", "D").WithLocation(7, 14));
     }
@@ -1851,13 +1851,13 @@ file class F { } // ok
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (1,19): error CS9052: File type 'C' cannot use accessibility modifiers.
+            // (1,19): error CS9052: File-local type 'C' cannot use accessibility modifiers.
             // public file class C { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeNoExplicitAccessibility, "C").WithArguments("C").WithLocation(1, 19),
-            // (2,21): error CS9052: File type 'D' cannot use accessibility modifiers.
+            // (2,21): error CS9052: File-local type 'D' cannot use accessibility modifiers.
             // file internal class D { } // 2
             Diagnostic(ErrorCode.ERR_FileTypeNoExplicitAccessibility, "D").WithArguments("D").WithLocation(2, 21),
-            // (3,20): error CS9052: File type 'E' cannot use accessibility modifiers.
+            // (3,20): error CS9052: File-local type 'E' cannot use accessibility modifiers.
             // private file class E { } // 3, 4
             Diagnostic(ErrorCode.ERR_FileTypeNoExplicitAccessibility, "E").WithArguments("E").WithLocation(3, 20),
             // (3,20): error CS1527: Elements defined in a namespace cannot be explicitly declared as private, protected, protected internal, or private protected
@@ -1895,13 +1895,13 @@ public class Derived2 : Base { } // 2, 3
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (2,7): error CS9053: File type 'Base' cannot be used as a base type of non-file type 'Derived1'.
+            // (2,7): error CS9053: File-local type 'Base' cannot be used as a base type of non-file-local type 'Derived1'.
             // class Derived1 : Base { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeBase, "Derived1").WithArguments("Base", "Derived1").WithLocation(2, 7),
             // (3,14): error CS0060: Inconsistent accessibility: base class 'Base' is less accessible than class 'Derived2'
             // public class Derived2 : Base { } // 2, 3
             Diagnostic(ErrorCode.ERR_BadVisBaseClass, "Derived2").WithArguments("Derived2", "Base").WithLocation(3, 14),
-            // (3,14): error CS9053: File type 'Base' cannot be used as a base type of non-file type 'Derived2'.
+            // (3,14): error CS9053: File-local type 'Base' cannot be used as a base type of non-file-local type 'Derived2'.
             // public class Derived2 : Base { } // 2, 3
             Diagnostic(ErrorCode.ERR_FileTypeBase, "Derived2").WithArguments("Base", "Derived2").WithLocation(3, 14));
     }
@@ -1921,7 +1921,7 @@ interface Derived3 : Interface { } // 1
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (6,11): error CS9053: File type 'Interface' cannot be used as a base type of non-file type 'Derived3'.
+            // (6,11): error CS9053: File-local type 'Interface' cannot be used as a base type of non-file-local type 'Derived3'.
             // interface Derived3 : Interface { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeBase, "Derived3").WithArguments("Interface", "Derived3").WithLocation(6, 11));
     }
@@ -2026,7 +2026,7 @@ partial interface Derived : I2 { }
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (3,19): error CS9053: File type 'I1' cannot be used as a base type of non-file type 'Derived'.
+            // (3,19): error CS9053: File-local type 'I1' cannot be used as a base type of non-file-local type 'Derived'.
             // partial interface Derived : I1 { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeBase, "Derived").WithArguments("I1", "Derived").WithLocation(3, 19));
     }
@@ -2065,7 +2065,7 @@ public void F(I i) { } // 1
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,17): error CS9051: File type 'I' cannot be used in a member signature in non-file type 'C'.
+            // (7,17): error CS9051: File-local type 'I' cannot be used in a member signature in non-file-local type 'C'.
             //     public void F(I i) { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "F").WithArguments("I", "C").WithLocation(7, 17));
     }
@@ -2086,7 +2086,7 @@ void I.F(I i) { }
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,12): error CS9051: File type 'I' cannot be used in a member signature in non-file type 'C'.
+            // (7,12): error CS9051: File-local type 'I' cannot be used in a member signature in non-file-local type 'C'.
             //     void I.F(I i) { }
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "F").WithArguments("I", "C").WithLocation(7, 12));
     }
@@ -2171,19 +2171,19 @@ unsafe class Program
                 // (1,28): warning CS0649: Field 'S.X' is never assigned to, and will always have its default value 0
                 // file struct S { public int X; }
                 Diagnostic(ErrorCode.WRN_UnassignedInternalField, "X").WithArguments("S.X", "0").WithLocation(1, 28),
-                // (5,18): error CS9051: File type 'Container<S>' cannot be used in a member signature in non-file type 'Program'.
+                // (5,18): error CS9051: File-local type 'Container<S>' cannot be used in a member signature in non-file-local type 'Program'.
                 //     Container<S> M1() => new Container<S>(); // 1
                 Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M1").WithArguments("Container<S>", "Program").WithLocation(5, 18),
-                // (6,9): error CS9051: File type 'S[]' cannot be used in a member signature in non-file type 'Program'.
+                // (6,9): error CS9051: File-local type 'S[]' cannot be used in a member signature in non-file-local type 'Program'.
                 //     S[] M2() => new S[0]; // 2
                 Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M2").WithArguments("S[]", "Program").WithLocation(6, 9),
-                // (7,12): error CS9051: File type '(S, S)' cannot be used in a member signature in non-file type 'Program'.
+                // (7,12): error CS9051: File-local type '(S, S)' cannot be used in a member signature in non-file-local type 'Program'.
                 //     (S, S) M3() => (new S(), new S()); // 3
                 Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M3").WithArguments("(S, S)", "Program").WithLocation(7, 12),
-                // (8,8): error CS9051: File type 'S*' cannot be used in a member signature in non-file type 'Program'.
+                // (8,8): error CS9051: File-local type 'S*' cannot be used in a member signature in non-file-local type 'Program'.
                 //     S* M4() => null; // 4
                 Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M4").WithArguments("S*", "Program").WithLocation(8, 8),
-                // (9,24): error CS9051: File type 'delegate*<S, void>' cannot be used in a member signature in non-file type 'Program'.
+                // (9,24): error CS9051: File-local type 'delegate*<S, void>' cannot be used in a member signature in non-file-local type 'Program'.
                 //     delegate*<S, void> M5() => null; // 5
                 Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "M5").WithArguments("delegate*<S, void>", "Program").WithLocation(9, 24));
     }
@@ -2207,7 +2207,7 @@ void M<T>(T t) where T : C { } // 1
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (10,30): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'E.M<T>(T)'.
+            // (10,30): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'E.M<T>(T)'.
             //     void M<T>(T t) where T : C { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "C").WithArguments("C", "E.M<T>(T)").WithLocation(10, 30));
     }
@@ -2234,7 +2234,7 @@ file class C { }
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (7,{{17 + typeKind.Length}}): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'E<T>'.
+            // (7,{{17 + typeKind.Length}}): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'E<T>'.
             // {{typeKind}} E<T> where T : C // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "C").WithArguments("C", "E<T>").WithLocation(7, 17 + typeKind.Length));
     }
@@ -2282,7 +2282,7 @@ file class C { }
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (5,36): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'D2<T>'.
+            // (5,36): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'D2<T>'.
             // delegate void D2<T>(T t) where T : C; // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "C").WithArguments("C", "D2<T>").WithLocation(5, 36));
     }
@@ -2302,16 +2302,16 @@ record struct R2(C c); // 2
 
         var comp = CreateCompilation(new[] { source, IsExternalInitTypeDefinition });
         comp.VerifyDiagnostics(
-            // (3,8): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'R1'.
+            // (3,8): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'R1'.
             // record R1(C c); // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "R1").WithArguments("C", "R1").WithLocation(3, 8),
-            // (3,8): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'R1'.
+            // (3,8): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'R1'.
             // record R1(C c); // 1
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "R1").WithArguments("C", "R1").WithLocation(3, 8),
-            // (4,15): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'R2'.
+            // (4,15): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'R2'.
             // record struct R2(C c); // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "R2").WithArguments("C", "R2").WithLocation(4, 15),
-            // (4,15): error CS9051: File type 'C' cannot be used in a member signature in non-file type 'R2'.
+            // (4,15): error CS9051: File-local type 'C' cannot be used in a member signature in non-file-local type 'R2'.
             // record struct R2(C c); // 2
             Diagnostic(ErrorCode.ERR_FileTypeDisallowedInSignature, "R2").WithArguments("C", "R2").WithLocation(4, 15)
             );
@@ -2443,7 +2443,7 @@ public static void Main()
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (5,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (5,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C // 1
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(5, 16),
             // (15,15): error CS0122: 'Outer.C' is inaccessible due to its protection level
@@ -2484,7 +2484,7 @@ static void Main()
             // (5,15): error CS0117: 'Outer' does not contain a definition for 'C'
             //         Outer.C.M(); // 1
             Diagnostic(ErrorCode.ERR_NoSuchMember, "C").WithArguments("Outer", "C").WithLocation(5, 15),
-            // (5,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (5,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(5, 16));
     }
@@ -2581,7 +2581,7 @@ public static void Main()
                 // (1,1): hidden CS8019: Unnecessary using directive.
                 // global using static C;
                 Diagnostic(ErrorCode.HDN_UnusedUsingDirective, "global using static C;").WithLocation(1, 1),
-                // (1,21): error CS9055: File type 'C' cannot be used in a 'global using static' directive.
+                // (1,21): error CS9055: File-local type 'C' cannot be used in a 'global using static' directive.
                 // global using static C;
                 Diagnostic(ErrorCode.ERR_GlobalUsingStaticFileType, "C").WithArguments("C").WithLocation(1, 21),
                 // (5,9): error CS0103: The name 'M' does not exist in the current context
@@ -2620,7 +2620,7 @@ public static void Main()
                 // (1,1): hidden CS8019: Unnecessary using directive.
                 // global using static Container<C>;
                 Diagnostic(ErrorCode.HDN_UnusedUsingDirective, "global using static Container<C>;").WithLocation(1, 1),
-                // (1,21): error CS9055: File type 'Container<C>' cannot be used in a 'global using static' directive.
+                // (1,21): error CS9055: File-local type 'Container<C>' cannot be used in a 'global using static' directive.
                 // global using static Container<C>;
                 Diagnostic(ErrorCode.ERR_GlobalUsingStaticFileType, "Container<C>").WithArguments("Container<C>").WithLocation(1, 21),
                 // (5,9): error CS0103: The name 'M' does not exist in the current context
@@ -2791,7 +2791,7 @@ public static void Main()
         // 'Derived.C' is not actually accessible from 'Program', so we just bind to 'Base.C'.
         var compilation = CreateCompilation(new[] { source, main });
         compilation.VerifyDiagnostics(
-            // (16,20): error CS9054: File type 'Derived.C' must be defined in a top level type; 'Derived.C' is a nested type.
+            // (16,20): error CS9054: File-local type 'Derived.C' must be defined in a top level type; 'Derived.C' is a nested type.
             //     new file class C
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Derived.C").WithLocation(16, 20));
 
@@ -3212,7 +3212,7 @@ class D : C1 { } // 1
 
         var comp = CreateCompilation(source);
         comp.VerifyDiagnostics(
-            // (8,7): error CS9053: File type 'C' cannot be used as a base type of non-file type 'D'.
+            // (8,7): error CS9053: File-local type 'C' cannot be used as a base type of non-file-local type 'D'.
             // class D : C1 { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeBase, "D").WithArguments("NS.C", "NS.D").WithLocation(8, 7));
     }
@@ -3266,7 +3266,7 @@ public static void M(this string s) { }
 
         var comp = CreateSubmission(source1, parseOptions: TestOptions.Script.WithLanguageVersion(LanguageVersion.Preview));
         comp.VerifyDiagnostics(
-            // (5,19): error CS9054: File type 'C1' must be defined in a top level type; 'C1' is a nested type.
+            // (5,19): error CS9054: File-local type 'C1' must be defined in a top level type; 'C1' is a nested type.
             // static file class C1
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C1").WithArguments("C1").WithLocation(5, 19),
             // (7,24): error CS1109: Extension methods must be defined in a top level static class; C1 is a nested class
@@ -3376,14 +3376,14 @@ file class C { } // 1
         // from source
         var comp = CreateCompilation(source1);
         comp.VerifyDiagnostics(
-            // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+            // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
             //     file class C { } // 1
             Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16));
         var sourceMember = comp.GetMember<NamedTypeSymbol>("Outer.C");
         Assert.Equal("<>F0__C", sourceMember.MetadataName);
 
         var sourceType = comp.GetTypeByMetadataName("Outer.<>F0__C");
-        // Note: strictly speaking, it would be reasonable to return the (invalid) nested file type symbol here.
+        // Note: strictly speaking, it would be reasonable to return the (invalid) nested file-local type symbol here.
         // However, since we don't actually support nested file types, we don't think we need the API to do the additional lookup
         // when the requested type is nested, and so we end up giving a null here.
         Assert.Null(sourceType);
@@ -3515,19 +3515,19 @@ void M(C c)
         var type = (INamedTypeSymbol)model.GetTypeInfo(node.Type!).Type!;
         Assert.Equal("C@<tree 0>", type.ToTestDisplayString());
         Assert.Equal(tree, type.GetSymbol()!.AssociatedSyntaxTree);
-        Assert.True(type.IsFile);
+        Assert.True(type.IsFileLocal);
 
         var referencingMetadataComp = CreateCompilation("", new[] { comp.ToMetadataReference() });
         type = ((Compilation)referencingMetadataComp).GetTypeByMetadataName("<>F0__C")!;
         Assert.Equal("C@<tree 0>", type.ToTestDisplayString());
         Assert.Equal(tree, type.GetSymbol()!.AssociatedSyntaxTree);
-        Assert.True(type.IsFile);
+        Assert.True(type.IsFileLocal);
 
         var referencingImageComp = CreateCompilation("", new[] { comp.EmitToImageReference() });
         type = ((Compilation)referencingImageComp).GetTypeByMetadataName("<>F0__C")!;
         Assert.Equal("<>F0__C", type.ToTestDisplayString());
         Assert.Null(type.GetSymbol()!.AssociatedSyntaxTree);
-        Assert.False(type.IsFile);
+        Assert.False(type.IsFileLocal);
     }
 
     [Fact]
@@ -3550,7 +3550,7 @@ void M(C c)
         var type = (INamedTypeSymbol)model.GetTypeInfo(node.Type!).Type!;
         Assert.Equal("C", type.ToTestDisplayString());
         Assert.Null(type.GetSymbol()!.AssociatedSyntaxTree);
-        Assert.False(type.IsFile);
+        Assert.False(type.IsFileLocal);
     }
 
     [Fact]
@@ -3573,6 +3573,6 @@ void M(C<int> c)
         var type = (INamedTypeSymbol)model.GetTypeInfo(node.Type!).Type!;
         Assert.Equal("C<System.Int32>@<tree 0>", type.ToTestDisplayString());
         Assert.Equal(tree, type.GetSymbol()!.AssociatedSyntaxTree);
-        Assert.True(type.IsFile);
+        Assert.True(type.IsFileLocal);
     }
 }
diff --git a/src/Compilers/CSharp/Test/Syntax/Parsing/FileModifierParsingTests.cs b/src/Compilers/CSharp/Test/Syntax/Parsing/FileModifierParsingTests.cs
index 48663a9a18d3a..6f0c7f920f7fd 100644
--- a/src/Compilers/CSharp/Test/Syntax/Parsing/FileModifierParsingTests.cs
+++ b/src/Compilers/CSharp/Test/Syntax/Parsing/FileModifierParsingTests.cs
@@ -507,7 +507,7 @@ public void FileModifier_11(SyntaxKind typeKeyword)
             """,
             expectedBindingDiagnostics: new[]
             {
-                // (1,20): error CS9052: File type 'C' cannot use accessibility modifiers.
+                // (1,20): error CS9052: File-local type 'C' cannot use accessibility modifiers.
                 // public file {{SyntaxFacts.GetText(typeKeyword)}} C { }
                 Diagnostic(ErrorCode.ERR_FileTypeNoExplicitAccessibility, "C").WithArguments("C")
             });
@@ -540,7 +540,7 @@ public void FileModifier_12(SyntaxKind typeKeyword)
             """,
             expectedBindingDiagnostics: new[]
             {
-                // (1,19): error CS9052: File type 'C' cannot use accessibility modifiers.
+                // (1,19): error CS9052: File-local type 'C' cannot use accessibility modifiers.
                 // file public {{SyntaxFacts.GetText(typeKeyword)}} C { }
                 Diagnostic(ErrorCode.ERR_FileTypeNoExplicitAccessibility, "C").WithArguments("C")
             });
@@ -696,7 +696,7 @@ file class C { }
             """,
             expectedBindingDiagnostics: new[]
             {
-                // (3,16): error CS9054: File type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
+                // (3,16): error CS9054: File-local type 'Outer.C' must be defined in a top level type; 'Outer.C' is a nested type.
                 //     file class C { }
                 Diagnostic(ErrorCode.ERR_FileTypeNested, "C").WithArguments("Outer.C").WithLocation(3, 16)
             });
@@ -2137,7 +2137,7 @@ class C
             """,
             expectedBindingDiagnostics: new[]
             {
-                // (3,17): error CS9054: File type 'C.X' must be defined in a top level type; 'C.X' is a nested type.
+                // (3,17): error CS9054: File-local type 'C.X' must be defined in a top level type; 'C.X' is a nested type.
                 //     file record X();
                 Diagnostic(ErrorCode.ERR_FileTypeNested, "X").WithArguments("C.X").WithLocation(3, 17)
             });
@@ -2235,7 +2235,7 @@ file record X() { }
             """,
             expectedBindingDiagnostics: new[]
             {
-                // (3,17): error CS9054: File type 'C.X' must be defined in a top level type; 'C.X' is a nested type.
+                // (3,17): error CS9054: File-local type 'C.X' must be defined in a top level type; 'C.X' is a nested type.
                 //     file record X() { }
                 Diagnostic(ErrorCode.ERR_FileTypeNested, "X").WithArguments("C.X").WithLocation(3, 17)
             });
@@ -2330,7 +2330,7 @@ class C
             """,
             expectedBindingDiagnostics: new[]
             {
-                // (3,17): error CS9054: File type 'C.X' must be defined in a top level type; 'C.X' is a nested type.
+                // (3,17): error CS9054: File-local type 'C.X' must be defined in a top level type; 'C.X' is a nested type.
                 //     file record X;
                 Diagnostic(ErrorCode.ERR_FileTypeNested, "X").WithArguments("C.X").WithLocation(3, 17)
             });
diff --git a/src/Compilers/Core/Portable/PublicAPI.Unshipped.txt b/src/Compilers/Core/Portable/PublicAPI.Unshipped.txt
index 17ab31dc4cf39..5ff4e2f3841dd 100644
--- a/src/Compilers/Core/Portable/PublicAPI.Unshipped.txt
+++ b/src/Compilers/Core/Portable/PublicAPI.Unshipped.txt
@@ -114,4 +114,4 @@ virtual Microsoft.CodeAnalysis.SymbolVisitor<TArgument, TResult>.VisitProperty(M
 virtual Microsoft.CodeAnalysis.SymbolVisitor<TArgument, TResult>.VisitRangeVariable(Microsoft.CodeAnalysis.IRangeVariableSymbol! symbol, TArgument argument) -> TResult
 virtual Microsoft.CodeAnalysis.SymbolVisitor<TArgument, TResult>.VisitTypeParameter(Microsoft.CodeAnalysis.ITypeParameterSymbol! symbol, TArgument argument) -> TResult
 Microsoft.CodeAnalysis.Operations.BinaryOperatorKind.UnsignedRightShift = 25 -> Microsoft.CodeAnalysis.Operations.BinaryOperatorKind
-Microsoft.CodeAnalysis.INamedTypeSymbol.IsFile.get -> bool
\ No newline at end of file
+Microsoft.CodeAnalysis.INamedTypeSymbol.IsFileLocal.get -> bool
\ No newline at end of file
diff --git a/src/Compilers/Core/Portable/Symbols/INamedTypeSymbol.cs b/src/Compilers/Core/Portable/Symbols/INamedTypeSymbol.cs
index f8fab6b35decf..2a6a9ceb1ff8c 100644
--- a/src/Compilers/Core/Portable/Symbols/INamedTypeSymbol.cs
+++ b/src/Compilers/Core/Portable/Symbols/INamedTypeSymbol.cs
@@ -59,7 +59,7 @@ public interface INamedTypeSymbol : ITypeSymbol
         /// <summary>
         /// Indicates the type is declared in source and is only visible in the file it is declared in.
         /// </summary>
-        bool IsFile { get; }
+        bool IsFileLocal { get; }
 
         /// <summary>
         /// Returns collection of names of members declared within this type.
diff --git a/src/Compilers/VisualBasic/Portable/Symbols/NamedTypeSymbol.vb b/src/Compilers/VisualBasic/Portable/Symbols/NamedTypeSymbol.vb
index 7d30aafb6182c..f53888191d8c1 100644
--- a/src/Compilers/VisualBasic/Portable/Symbols/NamedTypeSymbol.vb
+++ b/src/Compilers/VisualBasic/Portable/Symbols/NamedTypeSymbol.vb
@@ -1216,7 +1216,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
             End Get
         End Property
 
-        Private ReadOnly Property INamedTypeSymbol_IsFile As Boolean Implements INamedTypeSymbol.IsFile
+        Private ReadOnly Property INamedTypeSymbol_IsFileLocal As Boolean Implements INamedTypeSymbol.IsFileLocal
             Get
                 Return False
             End Get
diff --git a/src/EditorFeatures/CSharpTest/Completion/CompletionProviders/KeywordCompletionProviderTests.cs b/src/EditorFeatures/CSharpTest/Completion/CompletionProviders/KeywordCompletionProviderTests.cs
index cfbc1cf8ddd02..d47ed942af886 100644
--- a/src/EditorFeatures/CSharpTest/Completion/CompletionProviders/KeywordCompletionProviderTests.cs
+++ b/src/EditorFeatures/CSharpTest/Completion/CompletionProviders/KeywordCompletionProviderTests.cs
@@ -726,7 +726,7 @@ file class C { }
                 """;
 
             // it might seem like we want to prevent 'file file class',
-            // but it's likely the user is declaring a file type above an existing file type here.
+            // but it's likely the user is declaring a file-local type above an existing file-local type here.
             await VerifyItemExistsAsync(markup, "file");
         }
 
diff --git a/src/EditorFeatures/CSharpTest/SymbolKey/SymbolKeyCompilationsTests.cs b/src/EditorFeatures/CSharpTest/SymbolKey/SymbolKeyCompilationsTests.cs
index 11acb20fafeb1..b3fcbbf29434d 100644
--- a/src/EditorFeatures/CSharpTest/SymbolKey/SymbolKeyCompilationsTests.cs
+++ b/src/EditorFeatures/CSharpTest/SymbolKey/SymbolKeyCompilationsTests.cs
@@ -290,7 +290,7 @@ file class C { }
 }
 ";
             // this should result in two entirely separate file symbols.
-            // note that the IDE can only distinguish file type symbols with the same name when they have distinct file paths.
+            // note that the IDE can only distinguish file-local type symbols with the same name when they have distinct file paths.
             // We are OK with this as we will require file types with identical names to have distinct file paths later in the preview.
             // See https://github.com/dotnet/roslyn/issues/61999
             var originalComp = CreateCompilation(new[] { SyntaxFactory.ParseSyntaxTree(src1, path: "file1.cs"), SyntaxFactory.ParseSyntaxTree(src1, path: "file2.cs") }, assemblyName: "Test");
@@ -306,7 +306,7 @@ file class C { }
         [Fact]
         public void FileType4()
         {
-            // we should be able to distinguish a file type and non-file type when they have the same source name.
+            // we should be able to distinguish a file-local type and non-file-local type when they have the same source name.
             var src1 = SyntaxFactory.ParseSyntaxTree(@"using System;
 
 namespace N1.N2
diff --git a/src/Features/Core/Portable/MetadataAsSource/AbstractMetadataAsSourceService.WrappedNamedTypeSymbol.cs b/src/Features/Core/Portable/MetadataAsSource/AbstractMetadataAsSourceService.WrappedNamedTypeSymbol.cs
index cb8972561e3ef..02a938f0e1094 100644
--- a/src/Features/Core/Portable/MetadataAsSource/AbstractMetadataAsSourceService.WrappedNamedTypeSymbol.cs
+++ b/src/Features/Core/Portable/MetadataAsSource/AbstractMetadataAsSourceService.WrappedNamedTypeSymbol.cs
@@ -144,7 +144,7 @@ public ImmutableArray<SymbolDisplayPart> ToMinimalDisplayParts(SemanticModel sem
 
             public bool IsNativeIntegerType => _symbol.IsNativeIntegerType;
 
-            public bool IsFile => _symbol.IsFile;
+            public bool IsFileLocal => _symbol.IsFileLocal;
 
             public INamedTypeSymbol NativeIntegerUnderlyingType => _symbol.NativeIntegerUnderlyingType;
 
diff --git a/src/Workspaces/CSharp/Portable/CodeGeneration/CSharpSyntaxGenerator.cs b/src/Workspaces/CSharp/Portable/CodeGeneration/CSharpSyntaxGenerator.cs
index aacfcd25d420d..a8f1d5188fcc7 100644
--- a/src/Workspaces/CSharp/Portable/CodeGeneration/CSharpSyntaxGenerator.cs
+++ b/src/Workspaces/CSharp/Portable/CodeGeneration/CSharpSyntaxGenerator.cs
@@ -1377,7 +1377,7 @@ public override SyntaxNode WithAccessibility(SyntaxNode declaration, Accessibili
                 {
                     // If user wants to set accessibility for a file-local declaration, we remove file.
                     // Otherwise, code will be in error:
-                    // error CS9052: File type '{0}' cannot use accessibility modifiers.
+                    // error CS9052: File-local type '{0}' cannot use accessibility modifiers.
                     modifiers = modifiers.WithIsFile(false);
                 }
 
diff --git a/src/Workspaces/CSharp/Portable/CodeGeneration/NamedTypeGenerator.cs b/src/Workspaces/CSharp/Portable/CodeGeneration/NamedTypeGenerator.cs
index 941fef327976a..63c5af4e9c3ee 100644
--- a/src/Workspaces/CSharp/Portable/CodeGeneration/NamedTypeGenerator.cs
+++ b/src/Workspaces/CSharp/Portable/CodeGeneration/NamedTypeGenerator.cs
@@ -267,7 +267,7 @@ private static SyntaxTokenList GenerateModifiers(
         {
             var tokens = ArrayBuilder<SyntaxToken>.GetInstance();
 
-            if (!namedType.IsFile)
+            if (!namedType.IsFileLocal)
             {
                 var defaultAccessibility = destination is CodeGenerationDestination.CompilationUnit or CodeGenerationDestination.Namespace
                     ? Accessibility.Internal
diff --git a/src/Workspaces/Core/Portable/CodeGeneration/Symbols/CodeGenerationAbstractNamedTypeSymbol.cs b/src/Workspaces/Core/Portable/CodeGeneration/Symbols/CodeGenerationAbstractNamedTypeSymbol.cs
index bc12ff16bfbe4..75b3773b79b43 100644
--- a/src/Workspaces/Core/Portable/CodeGeneration/Symbols/CodeGenerationAbstractNamedTypeSymbol.cs
+++ b/src/Workspaces/Core/Portable/CodeGeneration/Symbols/CodeGenerationAbstractNamedTypeSymbol.cs
@@ -122,6 +122,6 @@ public override string MetadataName
 
         public bool IsSerializable => false;
 
-        public bool IsFile => Modifiers.IsFile;
+        public bool IsFileLocal => Modifiers.IsFile;
     }
 }
diff --git a/src/Workspaces/Core/Portable/Editing/DeclarationModifiers.cs b/src/Workspaces/Core/Portable/Editing/DeclarationModifiers.cs
index b53d401c8b683..bb425fbb78ab3 100644
--- a/src/Workspaces/Core/Portable/Editing/DeclarationModifiers.cs
+++ b/src/Workspaces/Core/Portable/Editing/DeclarationModifiers.cs
@@ -87,7 +87,7 @@ IMethodSymbol or
                     isExtern: symbol.IsExtern,
                     isAsync: method?.IsAsync == true,
                     isRequired: symbol.IsRequired(),
-                    isFile: (symbol as INamedTypeSymbol)?.IsFile == true);
+                    isFile: (symbol as INamedTypeSymbol)?.IsFileLocal == true);
             }
 
             // Only named types, members of named types, and local functions have modifiers.
diff --git a/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/SymbolKey/SymbolKey.NamedTypeSymbolKey.cs b/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/SymbolKey/SymbolKey.NamedTypeSymbolKey.cs
index 6b0fee736cd1e..f3c3e8d3f5e41 100644
--- a/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/SymbolKey/SymbolKey.NamedTypeSymbolKey.cs
+++ b/src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/SymbolKey/SymbolKey.NamedTypeSymbolKey.cs
@@ -16,7 +16,7 @@ public static void Create(INamedTypeSymbol symbol, SymbolKeyWriter visitor)
                 visitor.WriteSymbolKey(symbol.ContainingSymbol);
                 visitor.WriteString(symbol.Name);
                 visitor.WriteInteger(symbol.Arity);
-                visitor.WriteString(symbol.IsFile
+                visitor.WriteString(symbol.IsFileLocal
                     ? symbol.DeclaringSyntaxReferences[0].SyntaxTree.FilePath
                     : null);
                 visitor.WriteBoolean(symbol.IsUnboundGenericType);
@@ -84,19 +84,19 @@ private static void Resolve(
             {
                 foreach (var type in container.GetTypeMembers(name, arity))
                 {
-                    // if this is a 'file' type, then only resolve to a file-type from this same file
+                    // if this is a file-local type, then only resolve to a file-local type from this same file
                     if (filePath != null)
                     {
-                        if (!type.IsFile ||
+                        if (!type.IsFileLocal ||
                             // note: if we found 'IsFile' returned true, we can assume DeclaringSyntaxReferences is non-empty.
                             type.DeclaringSyntaxReferences[0].SyntaxTree.FilePath != filePath)
                         {
                             continue;
                         }
                     }
-                    else if (type.IsFile)
+                    else if (type.IsFileLocal)
                     {
-                        // since this key lacks a file path it can't match against a 'file' type
+                        // since this key lacks a file path it can't match against a file-local type
                         continue;
                     }