PUS meaning in Regional ?

Pashto (,; پښتو / Pəx̌tó, [pəʂˈto, pʊxˈto, pəʃˈto, pəçˈto]), sometimes spelled Pukhto or Pakhto, is an Eastern Iranian language of the Indo-European family. It is known in Persian literature as Afghani (افغانی, Afghāni).

Spoken as a native language mostly by ethnic Pashtuns, it is one of the two official languages of Afghanistan, and is the second-largest regional language in Pakistan, mainly spoken in the northwestern province of Khyber Pakhtunkhwa and the northern districts of the Balochistan province. Likewise, it is the primary language of the Pashtun diaspora around the world. The total number of Pashto speakers is at least 40 million, although some estimates place it as high as 60 million. Pashto is "one of the primary markers of ethnic identity" amongst Pashtuns.