It's a term from Scrum although I'm using it loosely. I'm referring to this thread.

For this reason in feedback threads it now makes more sense to replace suggestions with proposals. I suppose what we'll do for the most immediate case is revive the recent feedback thread (either I fudge its age to make it new again or sticky it). That will let people write in more formalized proposals. In three days we lock the thread or more generally don't consider proposals written after that. In one week we start the voting and consider that done after a few days (two or three). Everything will be done in a week, or stretch two weeks, after that the proposal is considered dead. That way we don't have code sitting around for several months gaining incompatibility with the site as the site changes.

Also please comment there, that thread didn't get the attention it deserved.