For a crying towel? To clean up the blood after they get beat up? No its to let the other emo’s know how they swing.  So what color do you wear?

Handkerchief code or hanky code (also known as bandana code and flagging) is a way of indicating, usually among gay male casual sex-seekers or BDSM practitioners in the leather subculture in the United States, Canada and Europe, whether they are a top or bottom, and what kind of sex they are seeking, by wearing cotton color-coded handkerchiefs (bandanas), usually in the back pocket. Hanky code was widely used in the 1970s as a gay code, however it is increasingly mainstream.

Today the bandanas are worn almost exclusively in the rear pocket, on the left side of the body for tops and on the right for bottoms, just as tops wear their keys on the left belt loop and bottoms on the right. In the past bandanas were also worn tied around the neck (with the knot positioned on either the left or right side); around the ankle (when wearing boots or when undressed); hung from the left or right side of the belt, or on other parts of the body.

Color Meaning Practice
Black SM Indicates the wearer’s interest in hardcore SM play, especially whipping.
Grey Bondage Play involving limiting the bottom’s ability to move or to escape.
White Mutual masturbation
Red Fisting
Light blue Oral sex
Navy Blue Anal sex
Pink (Hot Pink) Dildos
Charcoal Latex, PVC, or Rubber Fetish [3]
Yellow Watersports Urinating on (left), or being urinated upon by (right), another person
Medium Blue Uniform fetish Police uniforms or uniforms worn by other authority figures
Teal Cock and ball torture
Khaki Military Sex (Uniform fetish) Likes wearing military uniforms
Olive drab Military person [4] Left: A military top; Right: a military bottom
Kelly green sex for money Left: a male prostitute; right: a john (someone looking for a prostitute)
Hunter green Daddy/boy sex Looking for a boy (left) or looking for a daddy (right)
Brown Scat
Orange Few limits Wearers of orange bandanas are among the most experienced of leathermen or fetishists. Their fetishes are so numerous that the wearing of numerous bandanas would be impractical. When worn on the left, orange indicates that the wearer will top in relatively any fetish, anytime, anywhere. Conversely, when orange is worn on the right, it indicates the wearer will bottom in relatively any fetish, anytime, anywhere. Depending on the area you are from and the time frame orange on the right may mean not looking for any action right now. There is sometimes a stigma about “flagging” orange as it is sometimes thought that anyone willing to advertise an interest in “anything, any time, anywhere” is either mentally unstable or ignorant of what may really lay waiting.