The operation http://www.hl7.org/fhir/valueset-operation-expand.html on ValueSets contains among others the following two parameters:

• excludeNested 
• excludeNotForUI 

excludeNested

Proposal for renaming of excludeNested because of the uncertainty in the name:

• apply[Hierarchy|Nesting]FromCodeSystem 

or negated, so that the parameter values stay the same for systems, that already implemented this parameter:

• ignore[Hierarchy|Nesting]FromCodeSystem

Proposal for update of description of excludeNested:

"Depending on the server's implementation it may be that the server takes the hierarchy of the underlying CodeSystem for this ValueSet into account when creating the expansion. As a result the ValueSet expansion may nest codes or not (i.e. ValueSet.expansion.contains.contains). With excludeNested  true (default) the expansion will be flattened."

excludeNotForUI

Proposal for renaming of excludeNotForUI because of double negation in name: 

• forUI

Proposal for update of description of forUI:

The last sentence of the description would have to be updated: "In the FHIR Specification itself, the value set expansions are generated with forUI = true, and the expansions used when generated schema / code etc, or performing validation, are all forUI = false."