C.S. Peirce, from “Meaning,” 1910:
A sign may have more than one Object. Thus, the sentence “Cain killed Abel,” which is a Sign, refers at least as much to Abel as to Cain, even if it be not regarded as it should, as having “a killing” as a third Object. But the set of objects may be regarded as making up one complex Object. In what follows and often elsewhere Signs will be treated as having but one object each for the sake of dividing difficulties of the study. If a Sign is other than its Object, there must exist, either in thought or in expression, some explanation or argument or other context, showing how—upon what system or for what reason the Sign represents the Object or set of Objects that it does. Now the Sign and the Explanation together make up another Sign, and since the explanation will be a Sign, it will probably require an additional explanation, which taken together with the already enlarged Sign will make up a still larger Sign; and proceeding in the same way, we shall, or should, ultimately reach a Sign of itself, containing its own explanation and those of all its significant parts; and according to this explanation each such part has some other part as its Object. …
The Sign can only represent the Object and tell about it. It cannot furnish acquaintance with or recognition of that Object; for that is what is meant in this volume by the Object of a Sign; namely, that with which it presupposes an acquaintance in order to convey some further information concerning it. No doubt there will be readers who will say they cannot comprehend this. They think a Sign need not relate to anything otherwise known, and can make neither head nor tail of the statement that every Sign must relate to such an Object. But if there be anything that conveys information and yet has absolutely no relation nor reference to anything with which the person to whom it conveys the information has, when he comprehends that information, the slightest acquaintance, direct or indirect—and a very strange sort of information that would be—the vehicle of that sort of information is not, in this volume, called a Sign.
Two men are standing on the seashore looking out to sea. One of them says to the other, “That vessel there carries no freight at all, but only passengers.” Now, if the other, himself, sees no vessel, the first information he derives from the remark has for its Object the part of the sea that he does see, and informs him that a person with sharper eyes than his, or more trained in looking for such things, can see a vessel there; and then, that vessel having been thus introduced to his acquaintance, he is prepared to receive the information about it that it carries passengers exclusively. But the sentence as a whole has, for the person supposed, no other Object than that with which it finds him already acquainted. The Objects—for a Sign may have any number of them—may each be a single known existing thing or thing believed formerly to have existed or expected to exist, or a collection of such things, or a known quality or relation or fact, which single Object may be a collection, or whole of parts, or it may have some other mode of being, such as some act permitted whose being does not prevent its negation from being equally permitted, or something of a general nature desired, required, or invariably found under certain general circumstances.
CP 2.230-2
At this point it must be noticed that the simplest assertion uses two signs. This is true even of so simple a proposition as “pluit”, where one of the signs is the totality of the circumstances of the interview between the interlocutors, which makes the auditor think that what is happening out of doors is referred to. This is evident, since if he simply heard the word “pluit” pronounced, though he might be ever so determined to believe what was meant, yet if he knew not at all whence the sound came, whether from somebody recounting a dream or telling a story or from a planet of a distant star, and did not know at what time the word was uttered, he could not in the least guess what he was expected to believe. Nor could any mere words tell him, unless they referred to something in his immediate experience, as a sign (and if he were, for example, told that the rain was “fifty miles north of where you are standing.”) It must be something common to the experience of both interlocutors.
— Peirce, “Basis of Pragmatism”, 1905, MS 284, 42-3 [Stjernfelt 2014]