I don't know all the ins and outs, but this is what I have figured out.
MBR844C =
MB = Mag Bass series
R = Rod (G. Loomis also makes golf club shafts and other products)
84 = 84" or 7' long
4 = Heavy power (3= Med. Hvy., 2= Med. etc.)
C= Casting rod (as opposed to spinning )
MBR844C = MagBass rod, 7', heavy power, casting rod.
SJR722S = spin jig rod, 72" or 6', Med. (2 power), Spinning
SBR864C = Spinner Bait Rod, 86" (7'2"), Heavy Power, Casting
I hope this makes sense and is helpfull.
Ronnie