According to the Be nice policy:
Language likely to offend or alienate individuals or groups based on race, gender, sexual orientation, religion, etc. will not be tolerated. At all. (Those are just a few examples; when in doubt, just don't.)
I have recently flagged a comment that was saying:
You can't. Except for realized souls, Caste is the very core of Hinduism - the Brahmins even inserted a discriminatory verse into the Purusha Sukta of Rig Veda. If Caste goes away, Hinduism will go away.
But it was declined. I am not sure why it was declined?