Re: [CSS21] Comments on the 2003-09-15 CSS 2.1 Draft

On Monday, Oct 20, 2003, at 09:20 Europe/Helsinki, David Woolley wrote:

>> and when they are not. For interoperability and performance, it is
>> recommended that Web browsers not process the external DTD subset."
> That will break the rendering of the vast majority of current web 
> pages,
> including some commercially important features, like copyright symbols,
> because it will deny the use the full range of symbolic entities.

I was referring to XML DTDs. Not reading them does not affect the 
majority of the current Web pages, because the majority is using 

The copyright symbol (or any Unicode character for that matter) can be 
represented without entities.

> As I've said before the vast majority of tools that call themselves
> web browsers have built in knowledge of HTML DTDs and some even
> have make an attempt to obey them properly.

Real-world text/html browsers are tag soup processors, so the issues 
related to real XML DTD processing are of no concern to text/html 

> Your wording seems to be permitting the processing of internal 
> susbsets;

Yes. Perhaps it would be better to recommend that Web browsers not 
process the DTD at all. However, since Mozilla processes the internal 
subset, there may be a couple of actual use cases out there where that 
facility is actually used. (IIRC, you had to use the internal subset to 
declare IDness to the DOM until the DOM IDness was decoupled from DTD 
IDness. Compare with the definition of IDness in the CSS 2.1 Draft, 
BTW.) Anyway, those use cases are already incompatible with, for 
example, Safari which does not process the DTD at all.

> I thought that non-validating parsers were not required to handle
> any of the DTD at all.

They are required to check the internal subset for well-formedness.

[1] served as application/xhtml+xml

Henri Sivonen

Received on Monday, 20 October 2003 13:31:15 UTC