Side bar, I've always wanted to know this.. OBD, why do you call mobs MoBs? "Mob" is short for "Mobile Object," and if anything would be MOb.
I can't speak to "BETA" or "RAID" since NEITHER
is actually an acronym (which would warrant capitalization). Both are simple words where 'beta' is indeed the 2nd letter of the Greek alphabet and 'raid' is a quasi-military term used to describe a single fighting unit consisting of up to four 6-player groups.
As far as my use of the term 'MoBs', I always heard that it was a contraction (as opposed to an acronym) for mobile object with the 'Mo' coming from 'mobile' and the 'B' coming from 'object'. (The 's' just makes it plural!) I know it's unusual to drop the first letter of a word in a contraction but I don't think it's unheard of... honestly though, I would have to do some research to be sure...
At any rate, 'MoB' is the way I first saw it expressed (way back in the day when EQ live was the ONLY
MMO) and so that's the way I always type it... my recollection could be wrong, but check the ZAM EQ Live archives and I'll bet you'll see it that way in a bunch of posts (including mine!)