Specifications: HTTP Status Codes: http://www.restapitutorial.com/httpstatuscodes.html http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html http://www.restapitutorial.com/lessons/httpmethods.html
Complete decision diagram: https://raw.githubusercontent.com/for-GET/http-decision-diagram/master/httpdd.png
