The hypothesis of Achaemenid "alloglottography" (Gershevitch 1979) holds that Achaemenid Elamite was a medium for transmitting texts that were conceived and dictated in Old Iranian languages, to be read out and understood as Old Iranian texts . . .
— Matthew Stolper, 'Elamite', in Cambridge Encyclopaedia of the World's Ancient Languages
ref. is to: Gershevitch, Ilya, 1979, 'The alloglottography of Old Persian', Trans. Phil. Soc. London