I'm not asking how to detect duplicate POST requests. I'm asking if we are supposed to. According to RFC 2616 (section 9.5), POST is used to submit some sort of record/resource/data to the server ...

Nouns, verbs and well-formed URIs At the very least, a RESTful API respects REST's uniform interface constraint in two ways: Using nouns in RESTful URIs to ensure web service operations work on ...