 Amongst lay Zoroastrians, the three terms are used interchangeably.Unlike "mobed" but like "dastūr", "hērbad" may be adopted as a professional title in a person's name.Middle Persian 𐭧𐭩𐭫𐭯𐭲 "harpat" (Pahlavi "ʼyhlpt") derives from Avestan 𐬀𐬈𐬚𐬭𐬀𐬞𐬀𐬌𐬙𐬌 "aethrapaiti", which the Avesta uses denote a priestly teacher whose students ("aethrii") would be taught to recite the sacred texts.