When is it appropriate to respond with a HTTP 412 error?

Question

It is unclear to me when you should and should not return a HTTP 412: Precondition Failed, error for a web service? I am thinking of using it when validating data. For exa

Answer 1

412 is reserved for cases where the request is conditional, and the condition isn't met.

For your use case, 422 Unprocessable Entity is a good match.