UL 20:2018 General-Use Snap Switches.
2.1 The following definitions apply in this Standard:
2.2 CLEARANCES — Through-air spacing.
2.3 CREEPAGE DISTANCES (CREEPAGE) — Over-surface spacings.
2.4 DOOR SWITCH — A single-pole, momentary contact switch with a push-button actuator, provided with
an outlet-box and cover, It is intended for installation in door jambs to control lighting fixtures, typically in
2.5 FIXTURE SWITCH — A switch installed in the enclosure of a fixture such as a luminaire, a fan, or the like.
2.6 FLUSH SWITCH — A switch provided with a mounting yoke or integral flush device cover plate and intended for installation in or on an outlet box intended to control a branch circuit.
2.7 PENDANT SWITCH — A switch intended to be installed at the end of a flexible cord for use in branch-circuit pendant applications.
2.8 SELF-CONTAINED SWITCH — A switch intended for flush mounting without a separate outlet box for connection to one or more nonmetallic sheathed cables containing copper conductors.
2.9 SEPARABLE JUMPER CONNECTOR — Consists of shorted pins or tabs located within the body of the connector. It is intended to mate with a special purpose connector during an electrical installation to simulate an installed switch on a separable terminal assembly for the purpose of verifying circuit integrity.
2.10 SINGLE POLE, 3-WAY, 4-WAY, OR 2 POLE SWITCHES — Are intended to be installed on a single branch circuit controlling a single load. The circuit and load can be a phase to neutral (that is, 120V, 277V) or phase to phase (that is, 208V, 240V).
2.11 SURFACE SWITCH — A switch provided with a separable base and cover primarily intended for branch-circuit installation on exposed wiring consisting of open wiring on insulators or nonmetallic sheathed cable.UL 20 pdf download.