Should we trust business literature that celebrates managerial control of communication through the implementation of a hierarchically governed telephone network? Why, then, must firms like the Renault automobile company constantly recall the rules? My thesis is that these instructions, repeated in parrot-like fashion, reveal a failure of the head staff to control a technology in constant evolution that was adopted at minimum cost and assimilated by employees who adapt it to their own practical needs. I assert that visual documents constitute an interesting option in internal communication, one that literature on management has historically underestimated. How might they question the supremacy of written archives, on which most historical studies are based? What do visual documents specifically offer to the history of corporate telephone practices and oral business communication?