one period
road
Rd.
You put this at the end of a time if it's in the morning.
A.M.
As soon as possible
ASAP
weight
wt.
Doctor
Dr.
versus
You put this at the end if it's in the night.
P.M.
To be honest
TBH
inch
in.
Miss
Ms.
Boulevard
Blvd.
You put this at the end of a letter if you want to add more.
P.S.
I don't know
IDK
feet
ft.
Mister
Mr.
etcetera
etc.
United States
U.S.
For your information
FYI
yard
Junior
Jr.
number
no.
Used when introducing examples in writing.
e.g.
By the way
BTW
centimeter
cm.
Deoxyribonucleicacid
DNA