Does XML care about the order of elements?

Question

XML confuses me sometimes, but I\'m trying to get this figured out. What the vendor is telling me doesn\'t make sense but again, XML and I don\'t get along :)

I have

Answer 1

XML schemas can enforce element order. If there's no schema, neither order nor tags nor general structure not the kind of text (if it's a number or anything) is prescribed in any way - in theory. Of course that's not the case here.

It is perfectly possible to parse* data from XML without caring about order, but it can be easier (e.g. when using SAX, I imagine, or when you're a lazy bastard writing very sloppy code) to parse if you assume a certain order. Although they should include some schema if they want a certain order, it's perfectly possible that their parser chokes on it anyway. Yes, they shouldn't do this, but obviously they don't care.

*By "parsing" I don't mean "take that XML document and turn it into e.g. a DOM", but "take that e.g. DOM and extract the information from it".