DDEX messages allow, in certain places, to place the same tag, with different content, side-by-side. For example:
<UseType> Download </UseType> <UseType> PerformInPublic </UseType>
This XML snipped changes it's semantic depending whether it is an instruction ("you may use the content in the following way") or a report ("I have used the content in the following way").
In instructions – i.e. in a release delivery of licence request/grants – it is an OR (i.e. "you may offer the content as a download or for a public performance").
In reports – i.e. in a sales reports of invoices – it is an AND (i.e. "I have offered the content as a download for public performance").
The semantics of repeating tags in XML changes by type of message: