The terms "top" and "bottom" are also used: the top is the instigator of an action while the bottom is the receiver of the action.
Given the wide range of practices, some of which may be engaged in by people who do not consider themselves as practicing BDSM, inclusion in the BDSM community or subculture is usually dependent upon self-identification and shared experience.
and is interpreted as a combination of the abbreviations B/D (Bondage and Discipline), D/s (Dominance and submission), and S/M (Sadism and Masochism).
Some BDSM practitioners prefer a code of behavior that differs from "SSC" and is described as "risk-aware consensual kink" (RACK), indicating a preference for a style in which the individual responsibility of the involved parties is emphasized more strongly, with each participant being responsible for his or her own well-being.
Advocates of RACK argue that SSC can hamper discussion of risk because no activity is truly "safe", and that discussion of even low-risk possibilities is necessary for truly informed consent.
Use of the agreed safeword (or occasionally a "safe symbol" such as dropping a ball or ringing a bell, especially when speech is restricted) is seen by some as an explicit withdrawal of consent.
Failure to honor a safeword is considered serious misconduct and could even change the sexual consent situation into a crime, depending on the relevant law, since the bottom or top has explicitly revoked his or her consent to any actions that follow the use of the safeword (see Legal status).
Individuals who can change between top/dominant and bottom/submissive roles—whether from relationship to relationship or within a given relationship—are known as switches.
The precise definition of roles and self-identification is a common subject of debate within the community.
Terminology for roles varies widely among the subcultures.