...the barrel message, though... who wanted to keep it, and why? They must have been under some misunderstanding... I mean, sure, leave it in as an option if someone says they want it for whatever reason, but it doesn't mean anything, does it?
I know that one person a while back thought that it told them to make more barrels, but I'm pretty sure that that is wrong... As I understand it, it has nothing whatsoever to do with the number of free barrels you have. It's just produced by random coincidence.
I was under the impression that the message happened because dwarves who plan on putting an item in a specific barrel don't "reserve" that barrel, so another dwarf can cut and reserve it for moving.. causing the first dwarf to give an error when they fail to find the specific barrel they'd been aiming for originally. It doesn't have anything to do with the number of free barrels you have, and doesn't refer to any event that the player can (or would want to) deal with; that's why I wanted to be able to turn the message off.
You could have a billion free barrels and only two dwarves, and if they happened to focus on the same barrel at the same time, you'd still get the message. This is more likely than you'd think even with a billion barrels, too, since they're both using the same barrel-selection algorithm and may be coming from the same general position relative to your stockpile.
Or am I wrong?