bramley - 8:30 pm on Mar 30, 2011 (gmt 0)
Seems the answer to my first question might be :
which matches :
accoeding to : [code.google.com...]
I assume it will match : /index.php?anyparameters
I'm still looking for an answer to the second question. Is it a case of disallowing ?a=
then allowing ?a=blah:text ?