The hanky code is more of a statement-an advertisement that acts as a conversation starter, rather than a questionnaire in itself.

Hanky codes, even the most frequently used Black & Gray, are not commonly used in general BDSM communities.

The hanky code, as we know it today, dates back to the 1970s. Starting in the Gay Community.

Back in the day, when you were out and about at a club, you wanted a way to see who was open to particular roles. i.e., top/bottom, which later expanded into more interests. The core list consists of ten basic colors, with other expanded lists one or two dozen, or more activities, and even incorporating other elements like lace or keys instead of hankies. Using this may be cumbersome as it can be challenging to notice tiny differences in colors, especially in a darker room or when actively moving around.

In BDSM, the two biggies are black, “S&M” (Heavy), and grey, “bondage.” You may find rope bottoms or fliers at conventions or other events, especially larger events that are open to filling their rope dance card, often wearing gray. It’s usually tied to their right ankle, as they may not be wearing much. You may find riggers wearing a hank of rope to display their status, but it’s less of a firm and obvious rule vs. the gray hanky the bottoms wear.

Rope people tend to pick gray, and without pockets, bottoms/bunnies tend to tie the hanky around their ankles.

Typically, in the LGBT, leather, and higher protocol communities, these hankies are folded in a particular way and worn in a pocket. Wearing it on the left being top in the activity, and the right side taking the bottom role.

The general rule is to pick up to three colors at a time, maximum. If you need more, use orange–down for anything. Which again means this is a conversation starter. However, sometimes, you’ll find colors sewn into people’s vests, especially if they have more interests. Different sub-communities may have a more niche way of displaying colors. I.e., red shoelaces.

(Hanky Code Wikipedia article )
Oversized list of Hanky Codes

• Black: S&M
• Dark Blue: Anal sex
• Light Blue: Oral sex
• Brown: Scat
• Green: Hustler/prostitution
• Grey: Bondage
• Orange: Anything goes
• Purple: Piercing
• Red: Fisting
• Yellow: Pissing
• Maroon: Blood