> I'm designing a document type. Is there any circumstance
> when you would advise me to use a Processing Instruction
> rather than an empty element with attributes? I can't think
> of one myself, but I'm sure the XML designers must have had
> something in mind.
Probably not.
PIs are extremely useful when adding information to documents with
frozen DTDs. For example, the proposed "xml:stylesheet" PI allows you
to attach a stylesheet to any XML document without having to
tamper with the document's DTD (as by adding a STYLE element
or attribute).
I can't see designing a new document type and using PIs, though.
As you say, elements or attributes do the work.
-- John Cowan http://www.ccil.org/~cowan cowan@ccil.org You tollerday donsk? N. You tolkatiff scowegian? Nn. You spigotty anglease? Nnn. You phonio saxo? Nnnn. Clear all so! 'Tis a Jute.... (Finnegans Wake 16.5)