Hi there Bob,

Yeah, like the good bel says, the group's been-there-done-that, but as an old YARTie myself (they don't call me YARTie Marty for nothing), I'll try to help you out here. Well before my time, but try these:

http://wordsmith.org/board/showthreaded.pl?Cat=&Board=words&Number=627,
in particular:
http://wordsmith.org/board/showthreaded.pl?Cat=&Board=words&Number=894
and the similar
http://wordsmith.org/board/showthreaded.pl?Cat=&Board=wordplay&Number=3086

I just used the Search button at the top and tried the word "invalid" on All Forums, All Posts.

And if you - or any other recent subscribers - are wondering what a YART is:
http://wordsmith.org/board/showthreaded.pl?Cat=&Board=words&Number=5453