On 29/11/2012 18:09, Olumide wrote: > Thanks. I've changed the <xs:unique>'s as follows because they can also > be nested in <Item>. Is this correct? Scratch that. Here's my latest attempt <xs:unique name="UniqueIdConstraint"> <xs:selector xpath=".//*"/> <xs:field xpath="@id"/> </xs:unique> - Olumide