Doghouse Leathers proudly supplies hankies to signal your handkerchief code, commonly known as flagging. Tops wear them on the left, bottoms wear them on the right, and different colors flag and signal to others discretely your fetishes and kinks. Into anal? Try blue. Like oral? Light blue. Grey is for bondage, red is for fisting, purple is for piercing, and yellow is for watersports. Of course, go all black for S&M. Have multiple? Flag multiple... of course there's orange, for "anything goes"!