The B-Wing was an assault starfighter used by the Rebel Alliance towards the end of the Galactic Civil War. Admiral Ackbar had a hand in designing this fighter, it also served as a light bomber.
The B-Wing served in the Battle Of Endor, though nobody saw it.
If didn't look like a 'B' at all. Ackbar tried to make the argument that it looked like the lowercase 'b,' but even that was a stretch.