It's well-established policy that English is required on Stack Exchange sites (language-specific sites aside). That policy led to the question of whether English means UK English or US English. The community decided that neither one was more correct than the other, and that it's not worth editing to change either one to the other.
The differences between US and UK versions of English are mostly confined to minor spelling differences. What happens when non-US/UK English — in practice, this generally means Indian subcontinent English — is thrown into the mix? We end up making lists of common idiomatic and grammatical errors, apparently. Until now, I have considered idioms like the ones on that list to be wrong, and have edited numerous posts to convert them to US English. Is that the right thing to do?
The heart of this question comes down to whether and when non-UK/US versions of English can be considered full dialects, equal in correctness to US and UK English for Stack Exchange purposes, as opposed to pidgins that need to be fixed. I'm hoping to not only get my specific question answered, but also to generate some discussion on how we know when a version of English is "English-y enough" or "correct enough" to be used on Stack Exchange sites.
N.B. As far as I know — and please tell me if I'm wrong — the rules of English grammar are the same in every variant of the language. That means nobody should hesitate to fix errors in grammar because of worries about dialectal differences.