RE: document() function and error-handling

> I'm really not trying to beat a nearly-dead horse here (I
> swear!), but the XML spec says in '2.6:
> [17] PITarget ::= Name - (('X' | 'x') ('M' | 'm') ('L' | 'l'))
>

This rule says that the name XML in any combination of upper-or-lower case
is forbidden. There's a rule elsewhere that says names starting with "xml"
are reserved for future standardization. Some parsers will give you a
warning if you use such names; and your application may break if W3C decides
to attach a special meaning to the name you have chosen for yourself. Since
there's an infinity of names that don't begin with "xml", it costs you
nothing to avoid this risk.

Michael Kay
http://www.saxonica.com/