Is there an HTTP status code which is appropriate to use for clients which send a bad hostname (or none at all) through SNI or the HTTP Host header?
An older question address how and why such requests happen in the first place as well as how you can technically deal with them in Apache. It does however not address the choice of status code for the response.
In the past I have implemented an HTTP proxy which would send status code 502 and an html page explaining why the error message was produced. My rationale for using 502 was an expectation that I would mainly see it due to misconfigurations which meant the proxy could not find a suitable backend. In reality it turned out to be much more frequent to simply see completely bogus hostnames.
Is there another status code which is more appropriate and clearly signals to the client that the server on this IP address does not recognize the value sent through SNI and/or the Host header?