The if_status tag is a conditional tag and always used as an opening and closing pair, like this…
<txp:if_status> ...conditional statement... </txp:if_status>
The tag will execute the contained statements depending on the requested page’s HTTP status condition. Normal pages result in a status code of “200”, while missing pages set Textpattern’s status to “404”.
This tag provides a method of sharing one page template between common pages and error pages, but including different output depending on the page’s HTTP status.
Conditionally display text on missing pages
<txp:if_status status="404"> <p>The page you requested could not be found.</p> </txp:if_status>