!!! Overview
[{$pagename}] is defined in [RFC 7231], section 6.5.4: 404 Not Found, as a [HTTP Status Code] to indicate the requested [Resource] was "Not Found" however the [client] was able to communicate with a given server.

A [{$pagename}] [Result Code] does not indicate whether this lack is temporary or permanent. If the server knows that this condition is likely to be __permanent__, a [HTTP 410] (Gone) should be used instead of a [{$pagename}] status.

!! More Information
There might be more information for this subject on one of the following:
[{ReferringPagesPlugin before='*' after='\n' }]