Kol Kavuah, Kol D'Parish (Bitul and Blios #61 - Shulchan Aruch YD 110:3)
Rabbi Dovid Cohen
Kol Kavuah, Kol D'Parish: כל קבוע, כל דפריש: Kavuah d'oraisah; Kavuah d'rabbanan; Kol d'parish; What is considered parish; Pesach. See seforim by Rabbi Cohen at www.kashrushalacha.com