In section 13.3.1 ServiceGroupRegistration: Service Data Declarations, I think 
the definition of MatchByLocatorEquivalence has a couple of errors or 
inconsistencies.

I think that the Complex type defined should be called 
MatchByLocatorEquivalenceType rather than MatchByLocatorEquivalence, to be 
consistent with other type names in the spec.

I think there should also be an element defined called 
MatchByLocatorEquivalence of type MatchByLocatorEquivalence so that the static 
SDE value, ogsi:removeExtensibility, defined below then correctly refers to an 
element rather than a type.
 .