Looking at the side cargo bays, they are labeled 1A, 2A, 3A from bow to stern, on the port side, and 1B, 2B, and 3B from bow to stern, on the starboard side. I think that’s really cool. However, there are two additional cargo bays on the stern of the ship, also labeled 1A (port), and 1B (starboard). I think those two bays should be labeled 4A, and 4B.
I think those stern labels are for a different kind of bay. They are not painted in the same color or labeled in the same font as the others. Just my guess.