Are subordinate or NSSR references mandatory?

[Robert Adelberg <[e-mail]>]

     Have a question regarding references.  Fred and I at the JITC are 
     preparing to revise the X.500 PICS (hopefully) for the last time and 
     have come across some ambiguity in the base standard.
     
     Long story
     
     It all started with the conformance requirement for minimum knowledge, 
     X.519, clause 9.2.2c. "A DSA shall conform to the minimal knowledge 
     requirements defined in ITU-T Rec. X.518 | ISO/IEC 9594-4;".
     
     BTW, Minimum knowledge requirements are actually defined in X.501, 
     clause 18.4 (unless there is a difference between minimal knowledge 
     and minimum knowledge.)
     
     The question is our interpretation of the minimum knowledge specified 
     in 18.4.1 - 18.4.4.
     
     18.4.1 Superior Knowledge - If the DSA is not a first-level DSA, 
     superior references are mandatory.
     
     18.4.3 Supplier Knowledge - If the DSA consumes, supplier references 
     are mandatory.
     
     18.4.4 Consumer Knowledge - If the DSA supplies, consumer references 
     are mandatory.
     
     Finally, 
     18.4.2 Subordinate knowledge - "A DSA that is the master DSA of a 
     naming context shall maintain subordinate or non-specific subordinate 
     references of category master knowledge to each master DSA holding (as 
     master) an immediately subordinate naming context."
     
     Are we to assume that this translates into: If the DSA is not a 
     centralized (solitary) DSA the subordinate OR non-specific subordinate 
     reference are mandatory?
     
     Centralized DSA is define in the PICS to be: a DSA that is not capable 
     of holding knowledge information about other DSAs.
     
     And another thing, there is no ASN.1 definition for subordinate 
     knowledge as we assume it is some conglomeration of specific and 
     non-specific knowledge.
     
     That is our interpretation, any comments on this would be appreciated.
     
     
     
     Rob Adelberg
     OSE Lab, JITC
     Ft. Huachuca, AZ USA