This works for me, although I would prefer that this be a MUST. I don't see any logical situation where an RSO is running server software that cannot emit some configured string in an NSID response.
You mean you want a MUST for pointing to a geographical location? I think that's what you're implying but wasn't positive.
[I think it should be a SHOULD still, which implies "you really must unless you have some solid reason why not"]