Suggestions:
1. Bind url-insert to "M-i u" by default (this shortcut is currently
unused).
2. Most insert dialogues, e.g. insert URL and insert file, leave an empty
insertion if you cancel them. Others, e.g. insert reference, leave
nothing. The latter behaviour seems more sensible, and it'd be nice if all
dialogues (e.g. insert URL) had a cancel button. A little bit of
inconsistency seems to have crept into more recent additions to the
dialogue box set, perhaps because different authors have added them.
--
http://www.cl.cam.ac.uk/users/rrt1001/ | certain, a. insufficiently analysed
