"This IG does NOT mark any elements with the Must Support flag in its own profiles."

This IG has to use mustSupport.  Our profile on Questionnaire has to indicate which elements and extensions need to be supported.  The same is true on all other elements we define.  If an element is marked as mustSupport, that means it's fully optional - neither sender nor receiver need to have any support for the element, which is rarely what we want.

This IG should point to the HRex mustSupport rules and should also go through all profile elements and figure out which ones need to be mustSupport and which ones don't.