HTTP responses provide more information to clients about the outcome of a request, and many lesser-known status codes have interesting descriptions that can be compared to relationship problems. The 1xx status update codes indicate a request is still in progress, while the 2xx "it's all good" codes signify a successful response. Redirects are handled by 3xx responses like See Other, which redirects clients to a different resource after a PUT or POST request. Errors that are client fault (4xx) and server fault (5xx) provide information about what went wrong. Content negotiation (6xx) allows servers to determine which version of a resource to send back based on client constraints. Conflict (409) occurs when requests cannot be fulfilled, while the 410 "Gone" status code is returned when a resource no longer exists. The 417 Expectation Failed response indicates that a server has checked its capabilities and decided not to fulfill a request. Finally, the 425 Too Early response code ensures clients don't send encrypted data too early in an unencrypted request, while the 451 Unavailable for legal reasons error code comes into play when a government mandate prevents fulfillment of a request.