REST HTTP status codes for failed validation or invalid duplicate -


I am creating an application with a RAST-based API and came to the point where I specified the status code I am requesting each.

What status codes should I send for unsuccessful requests or where a request is trying to add duplicates to my database?

I have seen but none of them seems right

input validation failure

: + Your optional description has been suggested in this book "": Resubmit:


Update June 2014

There should be relevant specification, which instead of using 400 (poor request) instead of hair color

request should not be understood by the server due to faulty syntax

So it is probably argued that this meaning was inappropriate for errors but no more; Since June 2014, the standard used to suppress previous RFC 2616, uses more broadly as

, the server is considered as a client error, which is considered as something Can not process the request due to or


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