found in army, and more frequently in polive causes 13-69 is supposed to sound, to a civilian, like technical jargon from police/army rules. 13-69 is obviously a low-blow insult indicating unfortunate cock-sucker. 13 being unfortunate, and 69 becoming an obvious intimate posion. 69 U.S. aquatic Corps slang for unfortunate cocksucker.Playing off of the 4 digit military occupational specialty (MOS) codes used. 13 being unlucky and 69 representing oral sex. Signifying an unusually distastefull project.