In a triple trichotomy, these entities were classified as "icons," "indexes," or "symbols," by Charles Sanders Peirce.
A theory named for these entities distinguishes between sense, intention, and ideal worth, and was developed by Victoria, Lady Welby. These objects are studied by unifying theories of "extension" and "intension" (with an "s") or "comprehension" into one of "information." These entities were placed in a "triangle" along with subject and object in a book by C.K. Ogden and I.A. Richards. A theory of these entities throughout all of culture was deployed in The Limits of Interpretation and The (*) Role of the Reader. These "representamens" are part of a triadic relation that also includes their "interpretants," and they derive from the category of "thirdness." The study of these things "explains itself by itself" according to Umberto Eco. In a triple trichotomy, these entities were classified as "icons," "indexes," or "symbols," by Charles Sanders Peirce. For 10 points, name these entities that Ferdinand de Saussure divided into an arbitrarily-related signifier and signified. 
A theory named for these entities distinguishes between sense, intention, and ideal worth, and was developed by Victoria, Lady Welby.
signs [antiprompt on "symbols"; accept significs]