Namespaces

A name space associates a namespace prefix with some unique identifier (looks like a URL but isn't)

It is usually defined on the root element of a document (but need not be)

<root xmlns:mutt="mutt.co.uk"
            xmlns:jeff="www.jeff.org">

The namespace prefix can then be used to distinguish for example

<mutt:table> .... </mutt:table>
<jeff:table> .... </jeff:table>

An XML processor can be told to process elements from different namespaces differently