Funny you mention heathens, heretics and kafirs. All of these are people who are non-believers in their corresponding religions. Dalits are actually believers in Hinduism. No other religion in the world discriminates against the very people who chose to adopt it, except Hinduism.

I'll reiterate, it's very rare in other religions and uncommon. Mostly remnants of Hinduism. But ask an average muslim or a christian his caste and he will say that he doesn't have one.

> But ask an average muslim or a christian his caste and he will say that he doesn't have one.

Aren't there Shia/Sunni divisions and even centuries long wars?

Not exactly castes, but probably worse.

https://www.newstatesman.com/world/middle-east/2017/08/sunni...

Also see:

https://en.wikipedia.org/wiki/Caste_system_among_South_Asian...

It’s the same a catholic and Protestant.

Those terms do mean non-believer but they are also applied to followers with slightly different beliefs. Consider protestants, shias, ahmadiyas etc.

> But ask an average muslim or a christian his caste and he will say that he doesn't have one.

Almost 80% population of India is Hindu. It's obvious that relatively less number of muslims and even less number of christians are gonna talk about caste.