Although Old Persian also appears on some seals and art objects, that language is attested primarily in the Achaemenid inscriptions of Western Iran, suggesting then that Old Persian was the common language of that region. However, by the reign of Artaxerxes II, the grammar and orthography of the inscriptions was so "far from perfect" p. 53 that it has been suggested that the scribes who composed those texts had already largely forgotten the language, and had to rely on older inscriptions, which they to a great extent reproduced verbatim. p. 20.
