[kraker]

(...) there is no visual advisory on the displays that MUP is engaged, and legions of photographers pressed this matter on Canon for years. Woe betide you if you get the itch for a spontaneous from-the-hip shot and discover that faithful Brutus is in MUP and the choice moment has long gone.

MUP... MUP... I'm sure I've got an "Oh, of course, MUP!" moment coming up, but right now, I can't figure out what the TLA MUP stands for.