A dynamic transition of language signs appears to be the key issue in the semiotic project. This is, as Kevelson suspected, particularly of essence in law and legal discourse. Semioticians thus determine the relations between meaning and reality so that we think to succeed to articulate "how things really are". Signs have for the lawyer legal quality because they reach him or her via legal discourse in his professional and social discourse. Legal signs are the result of a legal codification before a lawyer can unfold any legal activity. We thus consider the need to qualify (a) how signs become specifically legal, (b) whether there are parallel processes in other fields of professional signification, and (c) how the social field comes to accept those signs in their legal sense and evolves in accordance with the legal meanings of them.