supertypes of an attribute description

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At various times we (LDAPbis, LDAPext) have discussed
what are the supertypes of an attribute description
with multiple options, such as:
	sn;a;b

In drawing from these discussions, I believe there is
some agreement that the supertypes should be:
	sn;a (*)
	sn;b (*)
	sn
	name;a;b (*)
	name;a
	name;b
	name

(* direct supertypes)

This is consistent with:
	An AttributeDescription with one or more options is
	treated as a subtype of the attribute type without
	any options.

(and, I believe, most implementations).  However, this statement
can easily be misinterpreted as: 
	An AttributeDescription with one or more options is
	treated as a direct subtype of the attribute type without
	any options.

as LDAP/X.500 attribute type subtyping does not support multiple
inheritance.  I feel a clarification is in order, preferable
with an example (such as the one above).

Comments?

Kurt