What do all of the abbreviations I see here mean?

BF = Boy Friend (also sometimes best friend, breast-feeding or breakfast, depending on context!!)
BIL = Brother-In-Law
BTW = By The Way
CIO = Crying It Out
CM = CafeMom
DD = Dearest Daughter, Darling Daughter, etc
DF = Dear/Darling Fiance'
DH = Dear Hubby (Or Husband), Darling Hubby, Darn Hubby, Dumb Hubby, etc
DS = Dearest Son, Darling Son, etc (can also mean Direct Sales)
FC = Foster Child
FIL = Father-In-Law
FWIW = For What It's Worth
GF = Girl Friend
IKWYM = I Know What You Mean
IMHO = In My Humble/Honest Opinion
JK = Just Kidding
KWIM = Know What I Mean
LMAO = Laughing My A$$ Off
LMBO = Laughing My Butt Off

LOL = Laughing Out Loud or Lots Of Laughs
MIL = Mother-In-Law
OIC = Oh I See
OMG = Oh My Gosh
OP = Original Poster (question asker)
OTOH = On The Other Hand
PM = Private Message
POV = Point Of View
PP = Previous Poster
ROFL or ROTFL = Rolling On The Floor Laughing
ROFLMBO = Rolling On The Floor Laughing My Butt Off
SAH(M) = Stay At Home (Mom)
SD = Step Daughter
SIL = Sister-In-Law
SO = Significant Other
SS = Step Son
STBX = Soon To Be Ex
TMI = Too Much Information
TTC = Trying To Conceive
TY = Thank You
WTH = What The Heck

You can find even more abbreviations here!