Section 4.4 multiple fallback fatal errors

Section 4.4 states:

XInclude processors must <http://www.w3.org/TR/xinclude/#dt-must> 
perform fallback behavior in the event of a resource error 
<http://www.w3.org/TR/xinclude/#dt-resource-error>, as follows:

If the *[children]* of the |xi:include| element information item in the 
source infoset <http://www.w3.org/TR/xinclude/#dt-source-infoset> 
contain exactly one |xi:fallback| element, the top-level included items 
<http://www.w3.org/TR/xinclude/#dt-top-level-included-items> consists of 
the information items corresponding to the result of performing XInclude 
processing on the *[children]* of the |xi:fallback| element. It is a 
fatal error <http://www.w3.org/TR/xinclude/#dt-error> if there is zero 
or more than one |xi:fallback| element.


It is not clear from this whether multiple fallabck elements  are a 
fatal error if fallback processing is *not* performed. NIST test case 12 
suggests that it is, but that's non-normative. However, it is clearly 
not a fatal error for an xi:include element to contain zero xi:fallback 
elements unless there's a resource error. That suggests that it is also 
not a fatal error that there be multiple fallback elements unless 
there's a resource error.

I suggest that this be clarified in the spec, which ever way the 
clarification goes.

--
Elliotte Rusty Harold