Hello NSK,
Could you be more elaborate on that subject? Where is it stated?
I read that in a programmer's book, but I need to look at my bookshelf if you want specific title and author.
Oh, well... If it is not stated in the spec, the note in the programmer's book is worthless anyway. There might be xml parsers that have trouble with both ways of coding. But that is not mediawiki's problem.
Patrick