Display and Designations overriding in a ValueSet instance

Hi all,

In the fhir specifications, we are allowed to override the concept’s display and designations in ValueSet’s instances. I would like to confirme tow things

  • when we override the diplay of a concept in a ValueSet instance, executing the $lookup operation on this concept should sebd back to us the “original” Display and not the “overrited” display ?
  • when we override the display of a concept in a ValueSet instance, executing the $expand operation on this VS instance, the server should send back the “overrited” display. The original display can be retreived by doing the $lookup operation.

Are these 2 statements correct and are they considered as rules and all the servers should conform them or they are only recommandations ?

Many thanks for your help.