I support creating a PI or element or attribute to indicate the location of an RNG schema. Looking at it in my own odd way, ANY implementation of RELAX NG is going to provide a way to associate a RNG schema with an instance anyway, if only as a command-line argument, so why not lend a hand and provide them with some additional guidance?
On the the other hand, what's to keep an implementation from recognizing a foreign attribute or element to have a similar role as a doctype declaration? Could we just simply add a compatibility element, not unlike <a:documentation>? Something like:
<c:schema href="http://www.anyurl.com/schema.rng"/>
Or merely an attribute:
<grammar c:href="http://www.anyurl.com/schema.rng"/>
Or a PI:
<?schema href="http://www.anyurl.com/schema.rng"?>
Would an attribute or element be preferred over a PI or easier to implement than a PI? If so, why?
Again, as I have mentioned earlier, I don't think we need to go as far as doing everything <!DOCTYPE> does. Or would we then be guilty of, as Mike Champion says, "civil disobedience"?
Mike
