Re: should CSS, HTML, etc. documents bear version information? (XMLVersioning-41?)

Elliotte Harold writes:

>  Really? Why? The must ignore semantics of HTML tend to mean that it has 

> a high degree of forward and backward compatibility.

Just because there's a useful default processing semantic doesn't mean 
there can't be reasons why it might be helpful to know what version the 
user thought (s)he was using.  First of all, it allows a knowledgeable 
client to interpret the document exactly as specified, should it wish to. 
One can imagine, for example, clients that fully understand several 
versions of HTML, but that intentionally do not implement features of 
newer versions when a document is tagged as being of a more limited one. 
Though it doesn't do rendering, I think the W3C HTML validator is an 
example of an application, albeit a special purpose one, that keys 
behaviour on the user's claim of what version of HTML has been used. 
Furthermore, I could imagine it contributing to error messages, management 
logs, etc.  Something like:  "If this Web page doesn't look right, click 
here for help.  ....  Which would get you "This page appears to have been 
authored using XHTML version 37;  the latest version supported by this 
browser is XHTML 1.0.  Perhaps that's why the page doesn't look right to 
you."

So, I think there are lots of reasons it could be valuable.

Noah

--------------------------------------
Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
--------------------------------------








Elliotte Harold <elharo@metalab.unc.edu>
04/04/2007 05:40 AM
 
        To:     noah_mendelsohn@us.ibm.com
        cc:     www-tag@w3.org
        Subject:        Re: should CSS, HTML, etc. documents bear version 
information?    (XMLVersioning-41?)


noah_mendelsohn@us.ibm.com wrote:

> Yes, of course.  In a typical HTML compound document page, HTML is 
indeed 
> one of the key vocabularies, and knowing it's version is truly useful. 


Really? Why? The must ignore semantics of HTML tend to mean that it has 
a high degree of forward and backward compatibility. Renderers can 
simply approach all HTML (especially all XHTML) as being an instance of 
the latest version they know about, recognize all the elements they 
recognize, and ignore the rest. It's not as if the meaning of anything 
actually changes from one version to the next. There are just new things 
added.

-- 
Elliotte Rusty Harold  elharo@metalab.unc.edu
Java I/O 2nd Edition Just Published!
http://www.cafeaulait.org/books/javaio2/
http://www.amazon.com/exec/obidos/ISBN=0596527500/ref=nosim/cafeaulaitA/

Received on Wednesday, 4 April 2007 21:50:37 UTC