Achaemenid Royal Inscriptions: collection of Old Persian cuneiform texts from the sixth, fifth, and fourth centuries BCE, left by the Achaemenid kings on their official monuments.

XSb, inscription on column bases from Susa

Inscription on a column base, Babylonian variant on XSc.

I am Xerxes, the great king, king of kings, king of all countries, king of the world, the son of king Darius, the Achaemenid.