Page tree



Reference set members can be added within an extension for a variety of reasons, including: 

  • To add members to a subset in the extension that is used nationally or locally
  • To adapt a reference set created by another organization, by adding new members that are required nationally or locally


Specifying members of a reference set can be done in different ways. It will depend on the requirements for the reference set what approach is feasible and possible. Please refer to the Practical Guide to Reference Sets for detailed instructions on the approaches and methods for identifying the SNOMED CT components that will be referenced by the members of the reference set.

However, each reference set member will be represented in the reference set in accordance with the following principles and process.

Reference set members may be added to reference sets belonging to modules in

  • The producers extension
  • The International Edition
  • Other extensions (which the producers extension modules are dependent on)

Reference set members created in the extension should be created within the module of the extension producer, so that it is possible to distinguish the reference set members created within the producers extension from reference set members created by other organisations (i.e. belonging to other modules).

Referenced Components

Even though the individual reference set members belong to the module of the extension producer, the actual components that are referenced by the reference set member, may belong to modules in 

  • The International Edition
  • The extension in which the reference set and its members are produced
  • Other extensions (which the producers extension modules are dependent on)


The table below provides a summary of the process to follow when adding members to a reference set.

File TypeProcess
Reference Set

A new refset row is created with a unique id. The data type for this id is UUID and the id can be generated using a UUID generator. Note that a namespace identifier will not be part of this id.

Versioning and module identification attributes are set accordingly:

  • effectiveTime is set to the date the extension will be published
  • active is set to reflect the status of the reference set member, i.e. 1 for active
  • moduleId is set to identify a module concept managed by the extension producer

Attributes common for all reference set types are set accordingly:

  • refsetId is set to the identifier of the concept used to identify and name the reference set. Note, the value of refsetId will be the same for all members in the reference set
  • referencedComponentId is set to the identifier of the SNOMED CT component or reference set, which is referenced by this specific reference set member
Attributes specific to the reference set type are set. For more information, please refer to the release file specification.

  • No labels