Local sets are a new construct for the creation of sets of concepts, similar to reference sets, but do not exist within a released or published edition or extension of SNOMED CT. This will give users without extensions or releases, the ability to create these sets of concepts and distribute them without having to create a release.

These local sets will look very similar to reference sets but will have the following different characteristics:

• The identifier of the local set is not validated as a valid SNOMED CT ID and therefore can be whatever the user wishes. This identifier is provided in the rf2 download in a column called localSetId (instead of the usual refsetId).
• The local set has no moduleId and is defaulted to '0' in the rf2 download.
• In the tool, where it currently provides the ability to 'Add Refset' there will be a second button, 'Add Local Set', which will display the same dialog box, but without the moduleId field (which is defaulted to 0).
• In the directory, these local sets need to be identified in the listing as a local set to differentiate from published, 'official' refsets

It should be made clear that if the user wants to include these sets in a release, then they would need to recreate the set as a reference set, with a valid refset id, namespace and module id, which in itself, means that they would need to have an initial release to include the reference set.

Refset impact

For reference sets, the main changes is that the refset id needs to be validated as a correct SCT ID, and will not progress without that.

Project Creation Impact

Some changes will be needed around project creation.

• Projects can only be created by admin staff
• Namespace must be added at project creation and cannot be edited after (aside from tool admins, not project admins)

tbc