This project uses the Data Documentation Initiative’s DDI 3.2 XML standard to document the SOC2010 occupation codes.
From ONS:
The standard occupational classification 2010 (SOC2010) is a common classification of occupational information for the UK.
Within the context of the classification, jobs are classified in terms of their skill level and skill content.
The classification is available in spreadsheet format 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