Pāṇini’s grammar of Sanskrit contains, among others, interpretative rules called paribhāṣās which guide the correct reading of grammatical rules expressed in a concise form by means of special terms, denotations and other shortening techniques. A careful study of Pāṇini’s grammar shows that paribhāṣās formulated by him are not enough to clarify all the nuances of various grammatical rules. Therefore commentators formulated additional paribhāṣās that allowed them to interpret correctly the rules of Pāṇini’s grammar and to resolve conflicts between the grammatical operations prescribed by it. Not only is a description of these additional interpretative rules unavailable in Russian literature, but even mentions of this phenomenon of Sanskrit grammatical literature are rare. The article highlights the history and principles of compilation of commented lists of post-Pāṇinian paribhāṣās by medieval Sanskrit grammarians of different schools. A comparative analysis of these lists is carried out and the traditional classification of paribhāṣās is discussed. It can be concluded that for at least one and a half thousand years (4th–18th centuries) a brief but exhaustive set of commented rules of interpretation of Pāṇini’s grammar was being compiled. The works of commentators differed both in the composition and order of presentation of the rules and in the understanding of each of them. This process was crowned by the 18th-century work of Nāgojībhaṭṭa, “The Lunar Diadem of Paribhāṣās” (Paribhāṣenduśekhara), which remains canonical today.
