200 OK

Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request, the response will contain an entity describing or containing the result of the action.

PATCH, mutating entities
200 OK, if the modification succeeded
Return codes and errors
POST and PATCH should never result in a 200 (generally 201, occasionally 202).
Caching
Responses with the following status codes should specify a Cache-Control header