What does Y/N stand for?

What does Y/N mean?

Y/N	Yes or No Business » General
Y/N	Yes or No Community » Educational
Y/N	Yes or No Community » Law
Y/N	Yes or No Computing » Assembly
Y/N	Yes or No Medical » Laboratory
Y/N	Yes or No Academic & Science » Universities
Y/N	Yes or No Governmental » Transportation
Y/N	Yes or No Governmental » US Government
Y/N	Yes or No Medical » Physiology
Y/N	Yes or No Medical » Veterinary
Y/N	Yes or No Governmental » Military