Here are some acronyms you may see people using on this forum and other forums on the internet. Please feel free to post others.
AFAIK - As Far As I Know
ASAP - As Soon As Possible
B1G1F - Buy 1 Get 1 Free
BB - Bulletin Board
B/C - Because
BF - Boy Friend or Best Friend
BIL Brother In Law
BOGO - Buy One Get One
BRB - Be Right Back
BTDT - Been There Done That
BTW - By The Way
CC - Credit Card
CIO - Cry it Out
DD - Dear/Darling Daughter
DH - Dear/Darling Husband
DIY - Do It Yourself
DS - Dear/Darling Son
EXP - Expiry date
FAQ - Frequently Asked Question
FIL - Father In Law
GC - Gift Certificate
GL - Good Luck
GP - General Practitioner
H/F - Handling Fee
HTH - Hope That Helps
ID - Identification/Identified
J/K - Just Kidding or Just Joking
JMO - Just My Opinion
JMTC - Just My Two Cents
KWIM - Know what I mean
LMK - Let me know
LOL - Laugh Out Loud
LMAO - Laughing my Ass off
LMBO - Laughing my butt off
MC - Manufacturer Coupon
MIL - Mother In Law
OB/GYN - Obstetrician/Gynecologist
OBO - Or Best Offer
OT - Off Topic
PM - Private Message
PMS - Premenstrual Syndrome
ROFL - Rolling On The Floor Laughing
SWAK - Sealed with a Kiss
Rx - Prescription
S&H - Shipping & Handling
SAHD - Stay at home dad
SAHM - Stay at home mom
SAHW - Stay at home wife
SIL - Sister In Law
SO - Significant Other
STD - Sexually Transmitted Disease
STQ - Skill Testing Question
TIA - Thanks in advance
TMI - Too much information
TTYL - Talk To You Later
TY - Thank You
UPC - Universal Product Code
UTI - Urinary Tract Infection
WAHD - Work at home dad
WAHM - Work at home mom
WTG - Way to go
WTH - What the heck
YW - Your Welcome
AFAIK - As Far As I Know
ASAP - As Soon As Possible
B1G1F - Buy 1 Get 1 Free
BB - Bulletin Board
B/C - Because
BF - Boy Friend or Best Friend
BIL Brother In Law
BOGO - Buy One Get One
BRB - Be Right Back
BTDT - Been There Done That
BTW - By The Way
CC - Credit Card
CIO - Cry it Out
DD - Dear/Darling Daughter
DH - Dear/Darling Husband
DIY - Do It Yourself
DS - Dear/Darling Son
EXP - Expiry date
FAQ - Frequently Asked Question
FIL - Father In Law
GC - Gift Certificate
GL - Good Luck
GP - General Practitioner
H/F - Handling Fee
HTH - Hope That Helps
ID - Identification/Identified
J/K - Just Kidding or Just Joking
JMO - Just My Opinion
JMTC - Just My Two Cents
KWIM - Know what I mean
LMK - Let me know
LOL - Laugh Out Loud
LMAO - Laughing my Ass off
LMBO - Laughing my butt off
MC - Manufacturer Coupon
MIL - Mother In Law
OB/GYN - Obstetrician/Gynecologist
OBO - Or Best Offer
OT - Off Topic
PM - Private Message
PMS - Premenstrual Syndrome
ROFL - Rolling On The Floor Laughing
SWAK - Sealed with a Kiss
Rx - Prescription
S&H - Shipping & Handling
SAHD - Stay at home dad
SAHM - Stay at home mom
SAHW - Stay at home wife
SIL - Sister In Law
SO - Significant Other
STD - Sexually Transmitted Disease
STQ - Skill Testing Question
TIA - Thanks in advance
TMI - Too much information
TTYL - Talk To You Later
TY - Thank You
UPC - Universal Product Code
UTI - Urinary Tract Infection
WAHD - Work at home dad
WAHM - Work at home mom
WTG - Way to go
WTH - What the heck
YW - Your Welcome