The native name of this people cannot be reconstructed with certainty. "Aryo-" (interpreted by some as meaning "those who plow"), sometimes upheld as a self-identification of the Proto-Indo-Europeans (see Aryan), is shown only in the Indo-Iranian subfamily, since it appears on written inscriptions; however, the Proto-Indo-Europeans themselves had not yet adopted writing, so there is no way to verify that "Aryo-" was their self-identification.