Routes
od or O.D. - Right eye
os or O.S. - Left eye
ou or O.U. - Each eye or both eyes
P.R. or PR - By rectum
po or P.O. or PO - By mouth
S & S - Swish and swallow
SL or s.l. - Sublingual route
SQ, sub q, subcut - Subcutaneous route
V or P.V. - Vaginal route
a.d. or A.D. - Right ear
a.s. or A.S. - Left ear