Sign (disambiguation)
A sign is an entity which indicates another entity. Sign may also refer to: == Communication == Signage, the use of signs and visual graphics to convey information Signature, a handwritten depiction of someone's name or other mark used as a proof of identity and intent Sign (semiotics), anything that communicates a meaning Sign language, a languages that uses the visual-manual modality to convey meaning == Mathematics == Sign (mathematics), an indication of negative and positive numbers Sign function, also known as the signum function Sign of a permutation of a finite set == Organizations == Project Sign, a project by the U.S. Air Force to investigate unidentified flying objects (UFOs) Scottish Intercollegiate Guideline Network, a Scottish group that develops evidence-based medical guidelines == Music == Segno (), a symbol used as a navigation marker in music; translated from the Italian word "sign" Sign (band), an Icelandic band Sign (Clock DVA album), 1993 "Sign" (Mr.