This acronym is very ripe for satire. My local public library is full of BOOCs, quite a few of which might be thought of as big, open, offline courses.

Dan Hickey explains: a BOOC is in fact a big open online course with up to about 500 members. This size limit is to enable more interactive, participitatory and socially-driven, though still teacher-managed, pedagogies in a large-ish setting without breaking the bank. It's an open and pedagogically enlightened version of the recently hyped SPOC or, as we normally refer to it, 'online course'. 

Dan's model is most interesting as a testbed for OpenBadges and the use of WikiFolios, allowing participatory, learner-driven and on-demand assessment in some very admirable and interesting ways. So, though the acronym is a little painful, the ideas behind the implementation itself are most cool. One to follow.