It has been unclear what should be used to populate ValueSet.version in the case of a ValueSet resource instance containing only an 'expansion' element without a 'compose' (i.e. a "naked expansion"). To clarify this, we need to add guidance to the http://build.fhir.org/valueset.html#expansion and http://build.fhir.org/valueset-operation-expand.html pages that states explicitly that ValueSet.version SHALL always be populated with the value of ValueSet.version obtained from the ValueSet resource instance (including a 'compose' element) that was used as the basis for the expansion (i.e. when the $expand operation was performed).

The ValueSet resource is normative, we will inform and solicit feedback from the implementer community on this clarification (i.e. Zulip implementer and terminology streams).