From PF: XHTML requirements: exploratory issues

Date: Tue, 5 Sep 2000 19:24:35 +1100 (EST)
From: Jason White <jasonw@ariel.ucs.unimelb.edu.au>
To: WAI Protocols and Formats <w3c-wai-pf@w3.org>
Message-ID: <Pine.SOL.4.10.10009051839380.10848-100000@ariel.ucs.unimelb.edu.au>
Subject: XHTML requirements: exploratory issues

Having read the minutes of the PF teleconference:

1. It is an essential requirement that the boundaries of any structural
division within a document be clearly identifiable. To that end, I would
favour the inclusion of a SECTION element (the name is merely illustrative
and not indispensable to the proposal), with an optional TITLE as its
first child:
<!element SECTION
(TITLE?,%BLOCK;*)>

Unless convincing counter-examples can be provided (of legitimate headings
to which no body text corresponds), the H1...H6 element should be deleted.

2. As exemplified above, TITLE should be an element made available in
appropriate contexts, rather than merely an attribute. Likewise, "text
equivalents should be expressed via an appropriate markup convention (for
example, in accordance with the model provided by OBJECT or SWITCH). The
latter should be generalized so as to encompass scripts, applets and other
external multimedia objects. This does not entail the construction of a
single, general-purpose inclusion element such as OBJECT; but it does
necessitate a flexible content model corresponding to any element that
permits the importation of programmatic or medium-specific resources into
a document. Text equivalents should likewise be available with respect to
client-side scripts, preferably, though not necessarily by means of the
same mechanism.

3. There may be additional structures, not presently reflected in HTML,
for which, owing to their ubiquity in the web environment, elements should
be defined. Groups of links constitute a highly pertinent example,
particularly with regard to recent extensions to the semantics of the MAP
element. To provide an adequate representation of navigational structures
as they appear in HTML documents today, it may legitimately be asked
whether any additional constructs should be developed specifically for
this purpose, separately from the ordered, unordered and definition lists
currently offered by HTML.

Another pattern of usage which is poorly captured at present, is the
identification, typically after a major heading near the beginning of a
document, of its authors. Often, heading elements are abused for this
purpose:
<h1>Document Title</h1>
<h3>Author's Name</h3>
<h2>First heading</h2> ...

One could argue that the name of the author is sufficiently important, not
only for presentational reasons but also to allow the generation of
metadata, that it should be clearly and explicitly identified by
appropriate markup.

I recognize, of course, that HTML can hardly capture the richness and
variability, both structurally and semantically, of the myriad document
types which are made available via the web. All that can be achieved in
the core of XHTML, is to provide markup conventions that are likely to be
used frequently across a variety of document types, leaving it to the
extension mechanism to permit the definition of more specific and
semantically precise constructs as the occasion demands. Thus, one needs
to be very careful in deciding which structures merit inclusion in the
predefined XHTML 2.0 modules, and in determining which semantic
distinctions genuinely need to be preserved, such that the structures
under consideration can not be adequately represented by more generic
elements.

Received on Tuesday, 10 October 2000 09:11:07 UTC