Property codeSystemVersion : WideString; (Read/Write)
If applicable, a version descriptor defined specifically for the given code system.
Different versions of one code system must be compatible. By definition a code symbol SHALL have the same meaning throughout all versions of a code system. Between versions, codes may be retired but not withdrawn or reused. Where the definition of the meaning of a code symbol changes, it must still be compatible (equal) between different code system versions.
Whenever a code system changes in an incompatible way, it will constitute a new code system, not simply a different version, regardless of how the vocabulary publisher calls it. For example, the publisher of ICD-9 and ICD-10 calls these code systems, "revision 9" and "revision 10" respectively. However, ICD-10 is a complete redesign of the ICD code, not a backward compatible version. Therefore, for the purpose of this datatype specification, ICD-9 and ICD-10 are different code systems, not just different versions. By contrast, when LOINC updates from revision "1.0j" to "1.0k", this would be considered as just another version of LOINC, since LOINC revisions are backwards compatible.