The string of digits to the left of the partition-identifier(in a short format SCTID) or to the left of the namespace-identifier(in a long format SCTID) is referred to as the item-identifier.

These values are available to uniquely identify an individual entity within the specified partition or namespace. The same item-identifier can be allocated in each partition of each namespace as the SCTID is rendered unique by the partition-identifier and the namespace-identifier. For components in the International Release of SNOMED CT, item-identifiers will usually be issued in the arbitrary order in which components are added to SNOMED Clinical Terms. However, due to management of the editing process the sequence of issued item-identifiers may be discontinuous.


In all cases, the value of an item-identifier on its own is meaningless. The only way to determine the meaning of an SCTID is by looking up the complete value in an appropriate distribution file.