Background

A SNOMED CT edition logically consists of the complete set of members of one or more modules.¹ Since the module dependency reference set (MDRS) tracks the explicit dependencies between a version of a module and all the versioned modules it depends on, a module identifier² is a natural identifier for an edition. When combined with a timestamp corresponding to a sourceEffectiveTime appearing in the MDRS, the module identifier can unambiguously identify a version of an edition.

Form

The URIs that identify unversioned editions (i.e. editions) and versioned editions (i.e. versions) take the following respective forms:

http://snomed.info/sct/{sctid}

http://snomed.info/sct/{sctid}/version/{timestamp}

Note, while it would be possible to extend this pattern to support multiple root modules, each with their own sourceEffectiveTime, this would introduce non-trivial complexities. For example, the modules they each depend upon may themselves overlap but have different versions (targetEffectiveTime) in which case the implied content would be inconsistent.

Examples

The following table shows some examples of URIs for editions and versions.

Table 2.1-1: Examples

 For a more extensive list of SNOMED CT edition URI examples, please refer to 4.4.2 Edition URI Examples