Longer, more elaborate lists may be found online, but many of the color variations in them are less often used in practice.

There is no single authoritative standard for the code, but there is broad agreement on the definition of certain colors. This table is drawn from Larry Townsend‘s The Leatherman’s Handbook II (the 1983 second edition; the 1972 first edition did not include this list) and is generally considered authoritative. Implicit in this list is the concept of left/right polarity, left as usual indicating the top, dominant, or active partner; right the bottom, submissive, or passive partner. Townsend noted that discussion with a prospective partner is still important because people may wear a given color “only because the idea of the hankie turns them on” or “may not even know what it means”.

The wearing of colored bandanas around the neck as a practical accessory was common in the mid- and late-nineteenth century among cowboys, steam railroad engineers, and miners in the Western United States. It is thought that the wearing of bandanas by gay men originated in San Francisco after the Gold Rush, when, because of a shortage of women, men dancing with each other in square dances developed a code wherein the man wearing the blue bandana took the male part in the square dance, and the man wearing the red bandana took the female part (these bandanas were usually worn around the arm or hanging from the belt or in the back pocket of one’s jeans).

The origin of the modern hanky code is disputed. The modern hanky code is often reported to have started in New York City around 1970, when a journalist for the Village Voice joked that instead of simply wearing a set of keys on one side or the other (then a common code to indicate whether someone was a “top” or a “bottom”), it would be more efficient to subtly announce their particular sexual focus by wearing different colored handkerchiefs. However, other sources attribute the expansion of the original red–blue system into today’s code to marketing efforts around 1971 by The Trading Post, a San Francisco department store for erotic merchandise, promoting handkerchiefs by printing cards listing the meanings of various colors. Meanwhile, Alan Selby, founder of Mr. S Leather in San Francisco, claimed that he created the first hanky code with his business partners at Leather ‘n’ Things in 1972, when their bandana supplier inadvertently doubled their order and the expanded code would help them sell the extra colors they had received.

The hanky code has recently undergone a revival and while the use of handkerchiefs may not be as prevalent, the hanky colors are a common consideration in the choice of leather and fetish gear color.

Social media may have lessened the use of hankies in cruising areas by digitizing the process. By using online platforms, men who have sex with men (MSM) can eliminate harassment and violence that they may face in public. Social networking services for MSM allow them to easily identify sexual interests without the need for physical apparel.