This project uses the Data Documentation Initiative’s DDI 3.1 XML standard to document the ISCO occupation codes.
From Wikipedia:
The International Standard Classification of Occupations (ISCO) is an International Labour Organization (ILO) classification structure for organizing information on labour and jobs. It is part of the international family of economic and social classifications of the United Nations.
The spreadsheet processed by this tool can be accessed here.
Again from Wikipedia:
The Data Documentation Initiative (DDI) is an international project to create a standard for information describing statistical and social science data. Begun in 1995, the effort brings together data professionals from around the world to develop the standard. The DDI specification, written in XML, provides a format for content, exchange, and preservation of information.
Download the resulting XML: isco.ddi3.xml
Joachim Wackerow originally marked up ISCO in DDI 3.0. His presentation about the project can be found here.