To shed a bit of objective light here.....I realize that many schools have many names for different things, sometimes they are right, sometimes they are close...it seems that mostly it comes from what people are told.
From a strictly linguistic perspective, none of the words that we are talking about are actually Korean - they are Hanmun; i.e. chinese written and pronounced in Korean (which means that they have the same meaning as the chinese word, but are pronounced differently).
I cannot comment on exact lengths and what constitutes the actual distinctions between staffs, but....
短棒 - Dan Bong - 단봉 - short stick
中棒 - Choong Bong - 중봉 - middle/center stick
長棒 - Chang Bong - 장봉 - long stick
and just for kicks.... 短刀 - Dan Do - 단도 - Dagger or short knife or short single edged sword
Like I said....that is what the words literally mean....what the lengths and distinctions are, I can't tell you; although, traditional Japanese full sized staff is 6 feet long (5.96ft, but who's counting) (六尺棒

...that would be the equivalent of a Chang Bong, although the Korean name would actually be yuk cheon bong or "six measure stick."