The affix vuñ comes in the sense of 'this is his' after the words denoting gotra (Patronymic\/Family-names) of Vedic schools.,
This debas अण् as well छ ॥ Thus gotra :- ग्लौचुकायनकम्, औपगवकम् ॥ According to Patanjali, the word चरण which ordinarly means Vedic School, means here duties or doctrines (dharma), and traditions (amnaya). Thus कठानां धर्म आम्नायो वा = काठकम् 'the dharma-Sutras or the tradition belonging to the school of Kathas'. So also कालापकम्, मौदकम्, पैप्पलादकम् ॥,