>>212348968I looked this up once and it seems they go overwhelmingly by things like clothing, mannerisms, vocabulary, customs and so on. But besides that, they can also go by ancestry. The upper castes in a given region know who the other "upper caste" families around are, so they would catch you lying because they would just call whoever is in the family you clain to be and ask "is this retard legit?" Or something like that. I think the main weakness of lying about your caste would be forging proofs of ancestry that don't hold up to scrutiny