Re: ISSUE-55: Re-enable @profile in HTML5 (draft 1)

Hi Henri,

You are right, but there's one small rider.

My recollection of the TF's discussion around @version is that it was
a way to allow RDFa consumers to decide whether they wanted to parse a
page or not.

It came about because some people were concerned that asking consumers
to parse every document in order to see if there was any RDFa present
was onerous. By providing @version, those consumers could choose to
only process documents that explicitly flagged up that RDFa was
present. Since these would probably be documents that the consumer had
themselves generated, then it wouldn't make any difference to anyone

But since we also didn't want to limit the use of RDFa to only those
publishers who had complete control over their pages, we didn't make
@version mandatory; RDFa as it stands can be placed in a blog post,
for example, without needing to change the blog sites templates.

This combination of factors is why you're not seeing @version used
much in the wild.

But you are right that from a *versioning* perspective, we don't need
to indicate a version until there is some different processing to do
-- such as a difference between a version 1.1 and 1.0.

However, at the moment, the problem with removing @version is that it
has been defined as a 'trigger' to indicate the presence of RDFa, so
that part needs to be taken into account.



On Mon, Sep 28, 2009 at 5:27 PM, Henri Sivonen <> wrote:
> On Sep 28, 2009, at 19:11, Toby Inkster wrote:
>>> This has not yet triggered the end of the world, so presumably RDFa in
>>> practice works fine without @version.
>> It is not surprising that RDFa *currently* works in practice without the
>> @version attribute, because *currently* only one version of RDFa is
>> defined.
> Defining versioning syntax now seems premature if the current de facto
> processing model is to ignore the versioning syntax (correct?) and the de
> facto authoring practice is not to emit the versioning syntax. If all goes
> well, versioning syntax is never needed.
> If things go wrong and in the future there is a need to signal versioning,
> that bridge can be crossed then and versioning syntax added.
> --
> Henri Sivonen

Received on Tuesday, 29 September 2009 01:48:44 UTC