>A #sign is something, A, which brings something, B, its #interpretant sign determined or created by it, into the same sort of correspondence with something, C, its #object, as that in which itself stands to C.
#CS_Peirce (1902)
In #Kihbernetics a sign is the #model describing (documenting) a #system ("mental model") abstracted from a real #phenomenon (object) by an #observer (the interpretant).