Support for Encodings is optional in specification narrative, but seems always required for Servers

"Section 5 Lobby says:
""Servers SHOULD include the encodings supported in the encodings Lobby Object. ""
But conformance clause says:
""5. The Lobby MUST provide a list of the encodings supported.""
Although technically it is OK for a conformance clause to strengthen a normative statement from the specification body, it is unclear why the Lobby section 5 from the start does not make the mandatory requirement itself. There does not seem to be another way to conform for Servers, that needs to keep that optionality."