Re: Registration of non-LDAP schemas?

[capple@xxxxxxxxxxxxxxxxxxxxxx (Christopher W Apple)]

Frank Dawson wrote:
>Chris Apple wrote, in part:
>
>"I would argue that DTDs for XML schema listings are part of the content
>and not of the metadata. Schema listing service metadata is used to catalog
>listings and should not contain information which actually helps to specify
>the details of a particular schema."
>
>I would disagree with your comment that DTDs are not part of the metadata
>of a schema. Indeed, the structural information in a DTD provides the
>relationship information about data in a schema. There is also information
>about the data type for the data in the schema. This is certainly "data
>about data". For example, a Document Type Definition tells one what
>elements the object may be composed of, but not what the elements semantics
>are. The inclusion of the DTD in the schema listing, versus a reference to
>the DTD is another story.
>
>- - Frank Dawson

A schema listing, in the context of the listing service that we
propose, is defined to be a combination of metadata and listing
content. Metadata, within the context of the listing service,
is limited to data about the listing, and will not include data
about the details of the listing content (which is what I think you
are describing above). References to listing content (in the case of
XML, I'm viewing a DTD as at least one part of the listing content)
are to be included in the listing metadata. Listing content and
listing metadata are currently prohibited from being stored in
the same file.

As an example, consider how you could use an argument similar to
that above to talk about how an LDAP object class really contains
metadata. Specifying one completely requires that you document its
optional and mandatory attribute membership and either include or
reference attribute type, attribute syntax, and matching rule
definitions. This clearly can contain "data about data" in a generic
sense. The concensus that we have to date is that each LDAP-specific
schema listing will have a single object class definition as its
listing content and that the listing metadata will include characteristics
of the listing such as who wrote it, when it was written or updated,
the listing title (in this case, object class name), the schema listing
name (unique across time within the service), references to schema
listing content both within and outside of the schema listing repository,
etc.

------------------------------------------------------------------------
Chris Apple                     Business Site: AnyWho Directory Service
Internet Directory Group                       http://www.anywho.com
AT&T Labs
capple@xxxxxxxxxxxxxxxxxxxxxx
+1 908 582 2409                 Tired of slow directories?  Try AnyWho.
------------------------------------------------------------------------