or maybe staff horses. Adapted from "Moving Pictures":
"Victor was introduced to the horse. It blinked its long eyelashes at him and appeared to chew soap. It looked like a horse that had had a long morning and wasn't about to take any shit from anyone. So far it had kicked three people.
‘What's it called?' he said cautiously.
‘We call it Evil-Minded Son of a Bitch,' said the groom.
‘That doesn't sound like a name.'
‘ ‘S a good name for this horse,' said the handler fervently.
Victor leaned close to the horse and whispered, ‘Look, I'm a friend, OK?'
Evil-Minded Son of a Bitch flicked a carpet-thick ear.
‘How do you ride it?' he asked the groom.
‘When you want to go forward you swear at it and hit it with a stick, and when you want to stop you swear at it and really hit it with a stick.'
‘What happens if you want it to turn?'
‘Ah, well, you're on to the Advanced Manual there."
EMSOAB should be on LOTS of stall nameplates.