The term Iran derives directly from Middle Persian Ērān, first attested in a 3rd-century inscription at Rustam Relief, with the accompanying <answer>Parthian</answer> inscription using the term Aryān, in reference to Iranians. The Middle Iranian ērān and aryān are oblique plural forms of gentilic ēr- (Middle Persian) and ary- (<answer>Parthian</answer>), both deriving from Proto-Iranian *arya- (meaning "Aryan," i.e., "of the Iranians"), argued to descend from Proto-Indo-European *ar-yo-, meaning "skillful assembler." In Iranian languages, the gentilic is attested as a self-identifier included in ancient inscriptions and the literature of Avesta,[a] and remains also in other Iranian ethnic names such as Alans (Ossetic: Ир – Ir) and Iron (Ossetic: Ирон – Iron).
What inscription referenced the term Aryan to Iranians?
Parthian