Re: X.500 Directory Schema

[Skip Slone <[e-mail]>]

> > 
> > Does there exist somewhere, a complete listing of the X.500 Directory
> > Schema?  I have a copy of the CCITT '88 series standard, but it only
> > lists a few basic object classes and attributes.  

The short answer to your question is "no" as explained below.

> It seems that the standards committee worked on adding extra services
> to the standard, rather than to add extra attribute types and object classes.
> 

This perception is pretty much on track.  In fact, we specifically limited the 
inclusion of schema elements to those that are deemed to be generally useful "by
a wide variety of applications ... and/or used by the Directory itself."  This 
text is taken from Clause 1 of X.520 | part 6, which goes on to say that there 
are two additional categories of attribute types:  those defined in other 
standards (specific to certain applications, messaging, for instance) and those 
defined by administrative authorities themselves.  Object classes are treated 
the same way. Thus, whenever someone comes up with an international standard on 
underwater basket weaving and wants to represent things like a "basket" object 
class and attributes like "water depth" or "water type (salt, fresh, clorinated,
etc.)," we don't have to be concerned with whether to go back and amend the text
of the Directory IS/Recommendation.

In other words, the committee members chose not to undertake such an arduous 
task as documenting all possible directory schema elements.  Thus, THE "X.500 
Directory Schema" is actually an open ended set made up of an indefinate number 
of smaller, application-specific collections of schema element definitions.  As 
such, it is infinitely extensible, giving the directory a much longer useful 
life than that of the committee.

  -- Skip