SD4 - Schema Format

SD4 - Schema Format
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Schemas are structured data, yet their current representation (DTD) does
not 
leverage work invested in the XML document instance. Tools and solutions
will be 
developed for XML in the following categories, and more besides: digital

signatures, structured attributes, specialized editors, indexing
services, 
repositories, version control systems, database representation, etc.
These XML 
tools will be mass market, and so will be ubiquitous, high-quality, and
expected 
by all users.

Further, in all our discussions with groups such as DSIG and W3C-Labels,
we 
found it artificial and difficult to make a clear distinction between
the 
requirements of schemata and the requirements of structured data
generally.

An example of this problem is the following: we want a mechanism to
digitally sign
a page on the Web by embedding a signature string in the page. Well, we
also need 
a mechanism to digitally sign a schema on the Web. If we keep the
instance syntax 
and the schema (DTD) syntax differents, we have to invent 2 different
mechanisms to sign them. 
And you can think about a thousand of similar problems.

Proposal: All machine-readable schemata, whatever their other
characteristics, 
are structured data, and so XML itself is a good carrier syntax for
schema 
expression. We should design a general structure for writing schemata in
XML.

In other worlds, we propose to keep the existing DTD syntax for
compatibility reasons 
and to define another syntax which will grand-father the current DTD
features but will
be using the current instance syntax (i.e. well formed tags and
attributes)

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Received on Friday, 16 May 1997 00:14:50 UTC