Hmm, recommendations do come back to haunt one. I guess I'd
sign up for part of that statement - putting URL^HIs in attribute
values rather than element content seems to be a basic part of Web
culture, and has come to feel natural.
But I'm on the record as saying I've never heard a convincing universal
decision procedure for what should be an element and what an attribute.
There are *some* things where it's easy - if you need further internal
structure, use an element, for example. But my beliefs on this are:
1. I have observed that humans doing document design are comfortable
with having two ways of labeling content, and assign things to
elements or attributes for reasons that seem good to them.
2. It is often the case, after designers have done this, that they
change their minds. I know I do.
3. For all of these reasons, if software needs to extract information
from XML documents, it should be prepared to extract it either
from character data or from attribute values, and not struggle
against what the designer decided.
-Tim