The referenced conformance classes should more clearly realte to this specification.

The conformance section does not list or identify any conformance clause. It talks of "conformance class", but these are defined externally to this specification. So it is not clear what it means when we read "these classes apply to this specification".
Does that mean that if my implementation satisfies "Class 4: Minimum Primitive Services Implementation" (externally defined) then it is conforming to this spec for this "class"? Or that it needs in addition to satisfy other conditions specifically stated for this spec, in that section ? (the latter, likely - but then we give to each of this class a different meaning from what they have in [ISO/IEC-BIAS)
There should be a list of named conformance clauses under that section, and each one clearly state the requirements it has. Some of that requirements can reference to the related "class" in ISO/IEC-BIAS, and others will be the additional ones specific to that spec.