SNOMED CT Extensions
A SNOMED CT extension is a set of SNOMED CT terminology components that extend and depend on the SNOMED CT International Edition. Components maintained in an extension are assigned to one or more dedicated modules included in the extension. Components created by Members or Affiliates of SNOMED CT International are identified by IDs that belong to a namespace identifier that belongs to the particular organization. Dependencies between modules are managed via entries in the Module Dependency Reference Set (for more details see Module dependencies). In terms of packaging, an extension can be published separately or along with all the dependencies (Editions).