I have this 404 redirection in my .htaccess file :
ErrorDocument 404 /404.php
It works fine when I try to access a page that doesn't really exist on my server.
The problem is that when I return my own HTTP 404 status in a page that really exists on the server, it doesn't redirect me to the 404.php page, but the browser displays a standard 404 error.
I return my own HTTP 404 status when I have a wrong url parameter for example.
Can you help me to define the rule in the .htaccess file, please?