The medieval inscription is defined as a material writing with the aim of the filling a specific function: guarantee a universal and long-lasting publicity. The importance of the material aspects and the context of the inscription allows speaking about «epigraphic object», a fusion of an objectal dimension and a textual one. Accordingly, the inscriptions can be analyzed as a discourse, which spreads at the same time on the scale of all the epigraphic production, as a genre, and in each of the realizations, unique on principle. The epigraphic discourse uses appropriate linguistic means which answer to its nature and function. In other words, it uses «codes». The codes are common principles of organization of the whole epigraphic discourse; they involve a significant arrangement of language; thanks to them the inscription exists and works as an inscription. Far from external rules stuck on the inscription, they are the condition of possibility of an epigraphic discourse, but mostly remain implicit; they are the manière to express in compliance with the semantic universe created by the inscriptions. Such a conceptual pattern, although matured by the epigraphic practice, must be put to the test of a documentation in which every element is singular by definition. The chosen ground of investigation concerns the inscriptions of Elne. From this documentation, our purpose is not to establish an exhaustive list of linguistic and graphic codes used in the inscriptions, but to ask a series of open questions. How to articulate the notion of discourse with that of code? What are the interactions between linguistic and graphic codes? Do the various codes possess autonomy or do they show a form of solidarity within a given discourse? Are there inscriptions with a lack of one or several code(s)? Are there inscriptions for which the code does not work? Must the codes be exclusively thought in terms of efficiency or operability? Does the functioning of the codes allow or not certain flexibility? The mobilization of the codes answers not only to the functioning of the inscription in terms of communication, but also to its identification as an inscription. It is because it mobilizes codes that it is considered and used as an inscription. They are thus useful for the writer and for the reader, but their necessity pertains more to pragmatics and aesthetics.