Re: ZIP-based packages and URI references into them ODF proposal

Ian Hickson wrote:
> On Tue, 30 Dec 2008, Julian Reschke wrote:
>> Ian Hickson wrote:
>>>> Of course it makes sense for a specification to state how 
>>>> extensibility works.
>>> Stating what the extensibility mechanisms of a language are, and 
>>> stating the future actions of as yet non-existent working groups, are 
>>> two very different things.
>> Yes. So what?
> 
> You asked for the latter. The spec already has the former.

Could you please elaborate?

Does the spec specify how to parse or serialize a future element called 
"foobar"?

> ...
>> That's a very verbose way to state "must ignore unknown values".
> 
> It's a precise way of saying it, that leaves nothing ambiguous. That's the 
> whole point.
> ...

I think the same precision can be reached with less verbosity.

>> So, if XML 1.0 *did* say that, how would you then introduce a new value? 
>> Older recipients would ignore it, after all.
> 
> If older recipients ignore the value, then we're golden. Just introduce 
> the new value, and then you have predictable down-level behavior and 
> predictable up-level behavior.

Well, if it's ok for consumers to ignore a new value, then this is the 
right approach. The problematic case is when that fallback behaviour is 
not sufficient.

Best regards, Julian