BYO?

so julia and i were just thinking
when you get an invite to something
and it says 'byo' on the bottom
what does that even mean?
obviously Bring Your Own, im not 100% retarded. but. seriously. any decent person would add a letter onto the end, to let people know what they want them to bring
i mean
bring your own could entail anything.
i could bring my own blanket? my own ham? my own dvd player? my own male-order husband? my own chocolate body paint? my own piggy bank? my own flag? my own history text book? my own beach ball? my own container of baby tomatoes? my own toilet brush? my own copy of clueless on dvd? my own shower radio? my own donuts?

specify people