A SNOMED CT International Release includes three distinct release types. Table 3.2-1 describes the release types and the differences between them.
Table 3.2-1: SNOMED CT Release Types
There are practical use cases for each Release Type.
- The full release allows access to all versions of the release. This is valuable for reviewing data entered using earlier versions and more generally supporting change management.
- The snapshot release only includes the latest version of each component. This can be useful to optimize access to the current version but does not provide access to earlier versions.
- The delta release only includes changes made between one version and the next. This provides a simple way to identify new and changed components to support change management and can also be used to update the previous version of the full release to the new version of the full release. However, the delta release cannot be used as a stand alone resource.
When considering which release type to use, it is worth noting that delta and snapshot views can be readily generated from the full release type. For this reason organizations that maintain SNOMED CT extensions are required to provide the full release type, while distribution of the other release types are optional.