Yes, it can get a bit confusing sometimes with all of the abbreviations and acronyms, but here is a running list of commonly used acronyms used on TK (The Knot).

AW              Attention Whore
BC, BCP     Birth Control, Birth Control Pills
BF               Boyfriend or Best Friend
BFF             Best Friend Forever
BM              Bridesmaid or Best Man
BP               Bridal Party
BTW           By The Way
C&P           Copy and Paste
DD             Dirty Delete
DF              Dear Fiance
DH             Darling Husband
DW            Destination Wedding
E-ring         Engagement Ring
E-party     Engagement Party
FG            Flower Girl
FI             Fiance
FIL           Father-In-Law
FILs          Future In-Laws
FBIL          Future Brother-In-Law
FFIL          Future Father-In-Law
FMIL         Future Mother-In-Law
FSIL          Future Sister-In-Law
F/U          Follow Up
FWIW       For What It's Worth
GBCK       Goodbye Cruel Knot
GBCN       Goodbye Cruel Nest
GF            Girlfriend
GM           Groomsmen
GTG         Knottie Get Together
HM           Honeymoon
HTH         Hope This Helps
IHO          In Honor Of
ILs            In-Laws
IMHO        In My Humble Opinion
IMNSHO    In My Not So Humble Opinion
JK             Just Kidding/Joking
JP/JOP      Justice of the Peace
LMAO       Laugh My Ass Off
LOL          Laughing Out Loud
LTBM        Living Together Before Marriage
MIL           Mother-In-Law
MOH        Maid/Matron of Honor
MUD         Made-Up Drama
NBR         Not Board Related
NFT         No Further Text
NH           New Husband
NMS         Not My Style
NWR        Not Wedding Related
OMG        Oh My God!
OOT        Out of Town
P&E          Planning and Etiquette Board
PIB            Pictures In Bio
PIP             Picture in Post
PSA          Public Service Announcement
RB            Ring Bearer
RD           Rehearsal Dinner
RP            Repost
ROTFL     Rolling On The Floor Laughing
SAHM       Stay-At-Home Mom
SAHW       Stay-At-Home Wife
SAHD        Stay-At-Home Dad
STDs         Save-The-Date Cards
SWR         Sort of Wedding Related
TIA           Thanks In Advance
TMI           Too Much Information
TOM         Time of Month
TY            Thank You
WP            Wedding Party
WR            Wedding Related
WTF          What The F*ck
WTH         What The Hell
WW           Weight Watchers
YGM          You Got Mail