Why does this rule use "MAY" instead of "SHOULD"? It seems like the intermediary should provide the reason for removing data. Otherwise, the recipient cannot distinguish between the sender not provider the data or it being removed during transit. It seems like for follow up purposes, the recipient should be able to distinguish those two options.

Existing Wording:

The Intermediary MAY provide the reason for the missing information using values (such as nullFlavors) from the value set where they exist or using the dataAbsentReason extension.