S/B = Starting Bid
R/B = Reserve Bid (or required bid), the minimum the seller will take
B/O = Buy Out, the auction is over and you get the item immediately
C/O = Current Offer
When R/B is reached you can add timer like selling in 24h. Most people add B/O When R/B is reached.
Like 50a RB Selling in 24h when R/B is reached B/O 80a