A code word that stops the SCENE cold. Used when someone has had all they can take, or in SCENES where resistance (“no! No! STOP”) is being played with, in order to distinguish a playful or in-role declaration of “stop” from a real “no, I really mean it, STOP”. This obviously varies with the individuals. Some use a system of “red (stop), yellow (slow down, lessen the intensity), and green (go ahead, dammit, I love it!)”, others just have one word. When the SUBMISSIVE/BOTTOM is gagged or for other reasons cannot speak, some specified signal, e.g., dropping a handkerchief, can serve as a safeword.