From openstack-dev list posting by me.
- 400: bro, something bogus happened, I'm pretty sure it was your fault
- 401: Tell me who you are and you might get to do this
- 402: You might get to do this if you pay
- 403: You didn't get to do this because the server forbids you
- 404: You didn't get to do this because it ain't there
- 405: You didn't get to do this because that action is not available
- 406: I've got the thing you want, but not in the form you want it
- 407: Some man in the middle proxy needs auth
- 408: You spoke too slowly for my awesome brains
- 409: Somebody else got there first
- 410: Seriously, it ain't there and it never will be
- 411: Why u no content-length!?
- 412: You sent conditional headers and I can't meet their requirements
- 413: Too big in the body!
- 414: Too big in the URI!
- 415: You sent me a thing and I might have been able to do something with it if it were in a different form