As an outsider, here's my take. The historic caste system included many restrictions on what people could do and who they could do it with. That's what was banned.
That said, there are a lot of ways to guess at caste if one is so inclined[1], and some people choose to use these guesses to discriminate. That's why it's a protected class --- it's not permissable to discriminate based on caste. There's also affirmative action for historically repressed castes, with all that comes with affitrmative action, for better or worse.
[1] caste related surnames and diet are the most easily understood by an outsider like me, but I think there may be caste related firstnames and other cultural indicators that I'm not aware of.
That said, there are a lot of ways to guess at caste if one is so inclined[1], and some people choose to use these guesses to discriminate. That's why it's a protected class --- it's not permissable to discriminate based on caste. There's also affirmative action for historically repressed castes, with all that comes with affitrmative action, for better or worse.
[1] caste related surnames and diet are the most easily understood by an outsider like me, but I think there may be caste related firstnames and other cultural indicators that I'm not aware of.