unimplemented schema elements (was: models-09 comments)

[Hallvard B Furuseth <h.b.furuseth@usit.uio.no>]

Kurt D. Zeilenga writes:
>At 08:45 AM 12/21/2003, Hallvard B Furuseth wrote:
>>draft-ietf-ldapbis-models-09.txt says:

>>> 7.1 Server Guidelines
>>>
>>>   Servers MUST recognize all attribute types and object classes names
>>>   defined in this document but, unless stated otherwise, need not
>>>   support the associated functionality.
>>
>>Move "unless stated otherwise" to the front of the sentence, since
>>extensibleObject is an exception to object classes which MUST be
>>supported.
> 
> No, support for extensibleObject feature is elective.  However,
> servers are to recognize the name 'extensibleObject'.

Is this a deliberate change from rfc2252?  I don't think that's what
rfc2252 means.  It says:

   4.4. Object Classes
   (...)
   Servers SHOULD implement all the object classes referenced in section
   7, except for extensibleObject, which is optional. Servers MAY
   implement additional object classes not listed in this document, and
   if they do so, MUST publish the definitions of the classes in the
   objectClasses attribute of their subschema entries.

   7.1. Extensible Object Class
   (...)
   Note that not all servers will implement this object class, and those
   which do not will reject requests to add entries which contain this
   object class, or modify an entry to add this object class.

I can find no mention in rfc2252 of servers having to recognize schema
elements they do not implement, such as extensibleObject.  The note in
7.1, which I previously mentioned is wrong when servers recognize
extensibleObject, makes perfect sense if rfc2252 means to say that
servers that do not implement extensibleObject will not recognize it.


I expect the answer to this is to point me at an earlier thread,
but:

What is the reason for requiring servers to recognize schema elements
they do not support anyway?  That is, [Models] 7.1 Server Guidelines:

  Servers MUST recognize all attribute types and object classes names
  defined in this document but, unless stated otherwise, need not
  support the associated functionality.  Servers SHOULD recognize all
  the names of attribute types and object classes defined in Section 3
  and 4, respectively, of [Schema].

As you said in this thread, schema elements that are recognized or
published but unsupported cause problems for clients.  I would think it
would make more sense if a server MUST NOT or at least SHOULD NOT
recognize or publish schema elements which are defined to have
functionality which the server does not support.

-- 
Hallvard