I was looking at the semantic distinction between "cql.anywhere"
and "cql.serverChoice", defined in the CQL Context Set at
http://www.loc.gov/z3950/agency/zing/cql/context-sets/cql.html
It seems  "cql.anywhere" tells the server to search all of its
indexes, though unspecified as to which those may be. On the
other hand, "cql.serverChoice" tells the server to search just
one index, though also unspecified as to which one.

I cannot imagine any searcher needing to insist that the server
limit its search to exactly one, unspecified index. Rather,
I would think the server should be free to search however many
indexes it wants to search. So, it seems more logical to me
that cql.serverChoice would be defined:

  that the server will choose one or more indexes for the given term

rather than:

  that the server will choose an index for the given term


Eliot