My opponent's name was actually "TheSuspiciousBanana", but it got truncated probably to leave room for the ELO. I suspect the ELO got left off because it was still too wide for the space left (maybe an off-by-one error when calculating the text width).
This happens to me plenty in full screen, too. $:^ P Now might be a good time to suggest that Elo show up in the little drop-down that appears when you click someone's name (whether or not it also shows next to a name during battle). This way, you can see the ratings on long usernames during battles and, just for kicks, during chats and stuff, too.
Yeah, that always annoys me when I try to find out somebody's ELO...and they don't happen to be in the multiplayer list of players (whether they're offline or playing campaign). Is there any alternative way of finding out?