•
ym – (s)
Yoctometre •
Ym – (s)
Yottametre •
YM – (s)
Yemen (FIPS 10-4 country code) – (i) Your Magazine (originally Young Miss, later Young & Modern) •
YMCA – (i) Young Men's Christian Association •
YMD – (s)
People's Democratic Republic of Yemen (ISO 3166 trigram, obsolete 1990) •
YMMD – (i) You Make My Day •
YMMV – (i) Your Mileage May Vary (adapted from the EPA's automobile mileage estimates, where it is used to convey the original meaning, "results may vary"); but (now) when used as an idiom, it -- (either the acronym "
YMMV" or the 4 words) -- can
instead mean (this e.g. comes from wikt:your mileage may vary#Phrase:) "this is just my opinion, your opinion may be different". == YN ==