Please do not consider yourself "thick" its actually a very complex subject and one I plan to write an overview on when I get time.
Bitstream is not a protocol, it is a bit representation on a timeslice basis for both the PULSE and the SPACE which makes up the PERIOD of one binary bit. The timeslice is the smallest time of any pulse or space.
What makes RC5 and RC6 protocols unique and more complex is they use what is called "Bi Phase Coding" which in practical terms means a rising edge within a time slice window is equal to a binary "1" and a falling edge represents a binary "0"
You ask, can the Beo5 actually support this ? the answer is YES
The best way forward is with an example, over the next couple of days I will convert a couple of commands and post them.