MediaWiki contains a dozen of variations on how to set the HTTP status code.
WebResponse->header( "HTTP/1.1 $code $message" ); WebResponse->header( "HTTP/1.1 302 " . HttpStatus::getMessage( 302 ) ); WebResponse->header( "HTTP/1.1 $code $message", true, $code ); WebResponse->header( "HTTP/1.1 403 $message", true, 403 ); header( "Status: $code $message", true, $code ); header( "Status: " . $this->mResponseCode, true, (int)$n ); header( "Status: {$this->httpCode} {$httpMessage}", true, $this->httpCode );
.. and many more.