Which of the following distinct types of 'usage' are/ are not allowed?
- Established usage
- Written usage
- Regional usage
- Colloquial usage
- Usage in email
- Usage on social media
- Verbal usage
Second, for each of those types, what sources can be used to document usage, and isn't this context-dependent? In particular, if we rely on dictionaries or style guides, we can only address 1, 2. So what sources do we use for 4.? (Not dictionaries, since they are lagging indicators by ~1-40 years) For 6. Social media, is it ok to cite a Twitter or Facebook search? How would we even find reliable contemporary sources for 7. Verbal usage at all? other than academic citations? And how would we resolve which one would be the most authoritative?
The about page claims "This site is all about getting answers. It's not a discussion forum. There's no chit-chat." On the face of it isn't even true for 3..7, since it implies there must be unambiguous authoritative reference(s) to resolve all questions asked on EL&U. So: what's the answer?
(Motivated by comments on sources to support whether 'hand in'/'hand-in' can be a noun, which as I already commented can't be resolved by Google N-gram, Google Book Search or any other online resource I'm aware of.)