M:
M8T = Mate
MHOTY = My Hat’s Off To You
MM = Market Maker
MorF = Male or Female?
MOTD = Message Of The Day
MOTSS = Members Of The Same Sex
MTFBWY = May The Force Be With You

MWBRL = More Will Be Revealed Later
MYOB = Mind Your Own Business
N:
N = And/Know/Now
NAK = Nursing At Keyboard
NAZ = Name, Address, Zip (also meansNasdaq)
NBD = No Big Deal
NBIF = No Basis In Fact
NFI = No Fing Idea
NFW = No Fing Way
NIFOC = Nude In Front Of The Computer
NM = Never Mind
NMP = Not My Problem
NMU = Nothing Much You