X.500 (was: DTD Question)

John Cowan (cowan@locke.ccil.org)
Thu, 22 Oct 1998 15:14:54 -0400

In a private mail I was asked for references on the X.500 schema.
The best short introduction I know is by Paul Barker at UCL:
http://homes.ukoln.ac.uk/~lisap/ccsap/Directory/Docs/prep.html .

RFC 1274 (http://www.isi.edu/in-notes/rfc1274.txt)
gives the whole deal for all the various ISO, Quipu, and
Pilot object classes.

Note that "classes" in X.500 are
more like Java interfaces: they allow multiple inheritance, and
an entry can belong to more than one class. Attributes are
multiple-valued, can be mandatory (not null) or optional
(may be null). "Attribute types" are essentially like Notations;
they specify the classes to which (immutable) values like names,
numbers, etc. belong.

Finally, RFC 2256 (http://www.isi.edu/in-notes/rfc2256.txt) gives
attribute-by-attribute guidance on meaning and usage for ISO
object classes.

-- 
John Cowan	http://www.ccil.org/~cowan		cowan@ccil.org
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)