4×× Client Error
405 Method Not Allowed
The method received in the request-line is known by the origin server but not supported by the target resource.
The origin server MUST generate an Allow header field in a 405 response containing a list of the target resource's currently supported methods.
A 405 response is cacheable by default; i.e., unless otherwise indicated by the method definition or explicit cache controls1.
405 Code References
Rails HTTP Status Symbol