Chuck Jones writes:
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.
For more on this discovery see:
The publication of this document also includes new photographs of other interesting documents in the Archive, including the Greek tablet and the Phrygian tablet.