1 definition by Webster's Comprehensive Dictionary

Noun. An Army term used for a prostitute. Originated during the Vietnam War, as soldiers would communicate a "Code 588" over the radio, meaning that they were approaching a brothel. Soldiers also used the term to refer to a good mood resulting from the use of a prostitute the previous night. In modern times, refers to any person, especially female, with prostitute-like qualities. See: prostitute, slut, whore
"We've got a Code 588 on the corner of 32nd and Main"
"Look at that girl, she sure is a 588"
"I'm Code 588, last night was really good"