Http REST status code for Resource Available and Not Available

Question

I am using HTTP HEAD request for checking is a userlogin name is available or not. Now I am returning a 200 OK response if the user login name is available, What do I return if login is not available? Should it be 409 or 403 or 410 (Gone).

Answer 1

I believe that 409 makes the most sense.

The request could not be completed due to a conflict (username already taken).

This code is only allowed in situations where it is expected that the user might be able to resolve the conflict and resubmit the request.

Your response body SHOULD include enough information for the user to understand the username is already taken.

Edit

The 410 Gone response should only be used if requested resource is no longer available at the server and no forwarding address is known. These are for situations where the request-URI is not available temporarily. Some suggest to just use 404 if you think the URI will be down for long periods.

The 403 indicates a fundamental access problem. It is more difficult to resolve because the HTTP protocol allows the Web server to give this response without providing any reason at all. This is equivalent to a blanket 'NO' by the Web server - with no further discussion allowed.