From
www.uo.com you can click the "support" section and go to game support. That'll take you to EA's support site where you can specify the game to be
UO, and type in search words to the knowledge base.
I just tried it, and typing in "toggle quest item" gives the exact answer to this problem.
They really should get all this stuff into the playguide at
uo.com though... but the knowledge base is a good place to look for now if you have a problem.