For the first time, a text has been found in Old Persian language that shows the written language in use for practical recording and not only for royal display. The text is inscribed on a damaged clay tablet from the Persepolis Fortification Archive, now at the Oriental Institute at The University of Chicago. The tablet is an administrative record of the payout of at least 600 quarts of an as-yet unidentified commodity at five villages near Persepolis in about 500 B.C.
“Now we can see that Persians living in Persia at the high point of the Persian Empire wrote down ordinary day-to-day matters in Persian language and Persian script,” said Gil Stein, Director of the Oriental Institute. “Odd as it seems, that comes as a surprise—a very big surprise.”
Until now, most scholars of Old Persian thought that Old Persian script and language were used only for the inscriptions of kings on cliff faces or palaces, or else to identify vessels of precious metals or other luxury goods that were connected with the kings and their palaces.
Another useful summary can be found on the Newswise website.
The full article can be found on the Achemenet website on the Arta online journal (2007.001). To see other article online at Arta (specializeing in Achaemenid research), you will need to navigate your way from the Achement website as follows: click on Ressources, then Engligne, then you can select from online journals Arta, Nabu and Jasr. Choose the one that you want to will then see a list of available papers. Arta is described as a "speedy vehicle for exchanging ideas and apreading news on excavations, publications, congresses, etc".