xml - How to define DTD without strict element order?

Question

As an XML "noob" I have discovered the importance of element order when creating an XML stream/file that is validated against a DTD. Is it possible to define a DTD that is not order dependent on elements ? If, so please provide syntactic example.

Answer 1

You use or (a vertical pipe) and repeat (an asterisk:)

<!ELEMENT eltype1 ( eltype2 | eltype3)*>

This means eltype1 can contain any number of repetitions of eltype2 or eltype3.