Formal subset/refset files are published in the main item releases. The releases of items in this category are provided so that subset memberships bound up in the main item releases can be quickly and easily accessed and viewed without specialist access to the whole of SNOMED CT. They are categorised by subject for convenience.
These files are not in an official SNOMED CT release format. NHS Digital publishes subsets in Microsoft Excel format solely for easy content preview. This file format does not support mandatory SNOMED CT change management and these files must not be used as the source of SNOMED CT data for live clinical systems.
Read more about SNOMED CT subsets and these spreadsheet files on Delen.
Find details about each subset on the Data Dictionary for Care site.