When posting a comment, the character count shows "n characters left", until you hit 1 character remaining - at which point, it switches to the singular. Fair enough.
But is 0 singular? Are negative numbers? Both use the singular phrasing, instead of plural. This is kind of a discussion point; personally, I'd have plural for any value except for "1 character", but I don't know what you think...
(Admittedly, it's a pretty darn minor point - I don't know how often the 600 character cap is hit, but I can't imagine it happens all that often...)
-∞
or-∞s
...