technical term (and reference) for "XML fragment"

Hi,

what's the preferred technical term (and a precise reference) for the 
thing that's frequently called an "XML fragment" (*)?

In the XML spec, <http://www.w3.org/TR/REC-xml/#NT-content> seems to be 
the right production, but "content" does not work well as term used 
outside the XML spec's context...

Feedback appreciated, Julian