attribute

The <attribute> element is used to specify the role of a certain attribute in the current document format.

<x:roleMapping>
  <x:element name="a" role="hyperlink"/>
  <x:attribute name="href" role="hyperlinkreference"/>

  <x:element name="picture" role="image"/>
  <x:attribute name="source" role="imagesource"/>
</x:roleMapping>

To specify the role of an attribute in a namespace, the namespace must be declared with a prefix.

<x:roleMapping xmlns:myprefix="http://www.example.com/xmlns/mynamespace">
  <x:element   name="myprefix:picture" role="image"/>
  <x:attribute name="myprefix:source"  role="imagesource"/>
</x:roleMapping>