[whatwg] [WA1] Versioning and Conformance Requirements

Thu Jul 7 07:17:44 PDT 2005

Ian Hickson wrote:
> On Wed, 6 Jul 2005, fantasai wrote:
> 
>>Two points:
>>
>>  1. The 'scheme' attribute from HTML 4 is missing. If there's
>>     a reason for this, please include a note stating the reason
>>     for removal (and thereby make the removal explict). Note that
>>     certain metadata formats (e.g. Dublin Core) do seem to be
>>     using this attribute.
> 
> 
> Nothing has been "removed". HTML5 is effectively a new language, which 
> just happens to be backwards compatible with HTML4.

# This specification represents a new version of HTML4 and XHTML1,
# along with a new version of the associated DOM2 HTML API.

> Only features that have well-defendable reasons to exist, along with
> solid use cases, are being added to the spec.

And what about features that are not part of the spec? For example,
if an HTML5 document includes elements and attributes (such as <blink>
or <meta scheme="..">) that are not described in your specifications,
is it still conforming?

> People will be encouraged to write documents listing the differences 
> between HTML5 and older versions of HTML, XHTML, and the HTML DOM when 
> HTML5 is stable, but there's no way HTML5 can include this information as 
> it would be a massive undertaking (only a small fraction of the hundreds 
> of elements, attribute, properties, methods, and interfaces that could be 
> included in the name of backwards-compatibility are being included).

Given that your spec claims to represent a later version of HTML and not
some unrelated language (and even uses XHTML 1.0's namespace), I think a
mention of any major changes from HTML 4.0 / XHTML 1.0 is nonetheless in
order. A full description of the changes and expansions is not necessary,
and would indeed be impractical, but you should call readers' attention
to changes that will affect migration from conforming HTML 4 Strict to
conforming HTML 5. For example, the requirement that <meta http-equiv>
only be used to express content encoding and only be placed as the first
element in <head> will make many conforming HTML 4 documents invalid
HTML 5.

Not having the time to compile such a list is no excuse for not having
one in the spec, as this is something that members of the discussion list
can certainly write /for/ you as an Appendix. (Such an exercise would
probably be best done at a more stable point in WA1's lifecycle, though.)

~fantasai