If you've been following this series on Builder.com, you already know that XML describes the structure of data and makes no assumptions about what the data it describes actually is, and whether that ...

XML has two main advantages: first, it offers a standard way of structuring data, and, second, we can specify the vocabulary the data uses. We can define the vocabulary (what elements and attributes ...

maybe just use an empty sequence as one of the choices?<BR><BR>XML schema have the smell of unneeded complexity. if you at all have the option check out Relax NG or one of the other alternatives.