I'll talk with respect to India. A bunch of dominant caste (including a decent chunk of middle caste and uplifted/politically represented lower castes) folks rent houses, of which, the upper castes are simply the worst kind of landlords.

A small minority of them don't discriminate, or disregard this, when money is involved. But most still do.

How exactly? They ask for your full government name - your surname speaks about your caste. But that would be really rude in the 21st century, right? How exactly do they mask casteism then?

Convey your caste using a lifestyle - "Oh, sorry, we don't allow non-vegetarians". This was literally our personal experience, especially in Mysuru, for the first time in my life. I was left stunned. And mind you, these people are educated, and have great jobs in the public sector.

In the Hindi-speaking belt, they are even more direct about their bigotry: "We only allow people who come from अच्छे घराने (acche gharane, meaning good families)". But you already know who the good, well-mannered families are, don't you?