yasya yal lakṣaṇaṁ proktaṁ puṁso varṇābhivyañjakam
yasya yal lakṣaṇaṁ proktaṁ puṁso varṇābhivyañjakam |
yad anyatrāpi dṛśyeta tat tenaiva vinirdiśet ||
(Śrīmad Bhāgavatam: 7.11.35)
“If a characteristic which is said to be an indicator of a person’s varṇa should be observed even elsewhere [i.e., even in a person born in a different varṇa], one should designate him [i.e., the person in whom the characteristic was observed] specifically with that [i.e., with the varṇa of that characteristic which was observed].”