Does HTML today comply with SGML?

Rich Wiggins (
Mon, 04 Apr 94 14:33:28 EDT

Our best Web-weaver, Chuck Henrich, and I are trying to resolve a simple
question: Does HTML comply with SGML? All along it's been my
interpretation that it does. By that I assume that it is possible
to take the Document Type Definition for HTML and feed that to
an SGML tool, and use that tool to validate HTML documents. Chuck
is under the impression that at least some aspects of HTML are not
compliant; ie one could not use a commercial SGML tool to validate
documents as used on the Web today.

If HTML doesn't comply, is it because of elements in the spec, or
because of commonly-used extensions?

If HTML does comply, is there anyone out there who actually uses
an SGML tool to verify their HTML documents? Or is this just
talked about? (There was a great deal of discussion a few months
ago as to the badness of using Mosaic or another browser as a
validation tool.)

How about the proposed HTML+ spec? Is it any more or less compliant
with SGML?

/Rich Wiggins, CWIS Coordinator, Michigan State U