jargon.artrocity.com
New Hacker's Dictionary the Jargon File v 4.4.6
[from the 1970 U.S. census forms via Usenet] Member Of The Same Sex, esp. one considered as a possible sexual partner. The gay-issues newsgroup on Usenet is called soc.motss. See MOTOS and MOTAS, which derive from it. See also SO.