501 / Not Implemented

“The server either does not recognise the request method, or it lacks the ability to fulfill the request.[2]“ — wikipedia

“The server does not support the functionality required to fulfill the request. This is the appropriate response when the server does not recognize the request method and is not capable of supporting it for any resource.“ — ietf

501 / code reference(s)
Rails HTTP Status Symbol
:not_implemented
← return