OK, grep -i tear-off /usr/share/gimp/2.0/help/en/* finds it. Gee, something I would never have encountered left clicking through life.
However still a little problem: m> after running the conversion, a second picking it out of the menus m> (or ALT i m i) just does nothing! It should become unselectable (greyed in the menus), and/or the message "already converted" should somehow be conveyed to the user. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]