I think that the word "semantics" is fine.
> - how do I add human 'meaning' to an object (e.g. an element or attribute)?
Documentation, lectures, email, lunch discussions.
> - how do I add machine 'meaning' to an object?
Computers aren't yet smart enough to understand anything. It will be
decades before you will be able to describe the concept of "title" to a
computer. All we can teach computers is *behaviour*: what to do with
various types of XML elements.
> At present there are *no* defined mechanisms for either of these in XML. I
> find this amazing and regrettable (I - and others such have Rick) have been
> shouting for it).
Well, the first is easy. I would be in favour of having the namespaces
spec. require the namespace PI point to documentation for a namespace.
Otherwise, we could easily develop another PI.
> Now compare MIME:
> If I get sent a file of type image/gif I can:
> - determine that 'image/gif' is a MIME type
> - see if it is in the central IETF registry. If so I can read the formal
> definition, etc.
Not all MIME types have formal definitions.
> - *and most important for me* I can associate the MIME type with a
> program through the mailcap file, *even if the MIME type is not
> registered*.
> This is all I am asking for, but there seems to be no way to do a similar
> thing for an XML element or attribute.
What would the program do? Print it? Search it? Convert it to another
format? If we restrict our discussion to printing: would it print it in
batch mode, or present a WYSIWYG view of it? would it print landscape or
portrait?
There are an infinite number of interesting behaviours that go with each
element type. How would the mailcap handle that?
> This is what I used to call semantics. If someone can come up with a better
> term, it would be useful. RickJ uses the word 'bind' - I like that.
Semantics are fine for human meaning. "Behaviour" seems okay for the
rest. Note that I even got the spelling correct.
Paul Prescod