Signals used in various kinds of transport:

Traffic light

Railway signal

Kent (game) a card game also known as Signal or Kemp

Cell signaling, in biology, the system of communication that governs basic cellular activities and coordinates cell actions

Signals (album), an album by progressive rock band Rush

Partnership card games (see Signal (bridge))

Signal (electrical engineering), a varying quantity that can carry information.

Signalling theory in biology, a theory stating how organisms signal their state to others

Signal (computing), an event, message, or data structure transmitted between computational processes

Signalling (telecommunications), a part of some communication protocols

Signalling (economics)

Signal Systems, a company of the McLean Group of Companies

Distress signal

Signals in legal citations

Beacons are aids to navigation devices. Intentionally conspicuous, beacons help guide navigators to their destinations. Beacon types include radar reflectors, radio beacons, and sonic or visual signals. Visual beacons range from small, single-pile...

Signals (military), a name that refers to military communications

Signaal (now Thales Nederland), a Netherlands based defence company

Signal processing, the field of techniques used to extract information from signals

Signal (toothpaste)

Signals and slots, a signal-driven software design pattern

Signal (band), a Bulgarian rock band

Signal programming, a variety of event-driven programming

Semaphore may be: Optical-telegraph systems: Semaphore line, a system of long-distance communication based on towers with moving arms Flag semaphore system Railway semaphore signal for railroad traffic control Other: Traffic semaphore, another name for...

Signal (magazine)

Signal (biology), an electrochemical communication activity in an organism

International maritime signal flags, using the International Code of Signals

Smoke signal (See also Category:Early telecommunications)

Signal 1 and Signal 2 radio stations