Question about default hex values for max player numbers on a server

Hello.

I was looking through the limit breaking list earlier, and noticed values I didn’t recognize at several places, and I noticed the max player number default value especially… Its 5b.

5B = 91, and the absolutely max default number of players is 128. 128 = 80 in hex.

Can someone explain this closer, as I’m pretty sure I did a horrible mistake somewhere?

EDIT: Oops, I saw wrong, its max characters per player. I wonder what the B is doing there though, can anyone explain that?

EDIT2: Also, before you suggest anything, I know its decimals, not hex… well, I do now at least.