204 No Content
204 No Content success status response code
indicates that a request has succeeded, but that the client doesn't need to navigate away
from its current page.
This might be used, for example, when implementing "save and continue editing" functionality for a wiki site.
In this case a
PUT request would be used to save the page, and the
204 No Content response
would be sent to indicate that the editor should not be replaced by some other page.
204 response is cacheable by default (an
ETag header is included in such a response).