A-B
AF: Aunt Flo (menstruation)
BIL: Brother-in-law

C-D
CTS: Consider the source
DB: Dear baby
DD: Dear daughter
DH: Dear (or darn) husband
DS: Dear son
DW: Dear (or darn) wife

F-H
FIL: Father-in-law
GF: Girlfriend
GMTA: Great minds think alike

M-N
MIL: Mother-in-law
NP: No problem

O
OIC: Oh I see
OT: Off topic
OTOH: On the other hand

R-S
ROFL: Rolling on the floor laughing
SAHD: Stay-at-home dad
SAHM: Stay-at-home mom
SIL: Sister-in-law
SO: Significant other

T
TIA: Thanks in advance
TPTB: The powers that be
TTC: Trying to conceive
TTFN: Ta ta for now
TTYL: Talk to you later
TY: Thank you

W-Y
WAHD: Work-at-home dad
WAHM: Work-at-home mom
WOHM: Work-out-of-home mom
WTG: Way to go