It should include that you need at least 100 points plus 2 days after the posting date to start a bounty.
(And on all SO sites' faqs. I mean on SU, DT, SF faqs, too.)
I don't think it has to be complete, and in fact there are many many things missing. Too much information for the sake of completeness will simply confuse newbies.
For example you don't need to know that you need 100 rep to open a bounty; if you want to open one you can just try and the system will tell you, why write it in the FAQ?
It also says: