QSD description for DAV:contains in DAV:basicsearchschema

Julian,

Section 5.19.8 of draft-reschke-webdav-search-14 requires that "All optional 
operators that are supported MUST be listed in the DAV:operators element. 
The listing for an operator consists of the operator (as an empty element), 
followed by one element for each operand. The operand MUST be either 
DAV:operand-property, DAV:operand-literal or DAV:operand-typed-literal 
(...)"

But the optional operator DAV:contains cannot be described in these terms, 
because
its content model is defined to be (#PCDATA) and there is no operand 
descriptor for #PCDATA content.

Is there any conforming way of describing DAV:contains?

IMHO, a possible solution would be defining a "DAV:operand-pcdata" element, 
so the following construct would be valid:

  <opdesc xmlns='DAV:'>
    <contains/>
    <operand-pcdata>
  </opdesc>


Regards,

Javier