Setting up a 404 page on your webserver was the easy part. Now you have found that your site or application has begun to exhibit strange behaviors with redirects or variable values or sessions. Find the real 404 Not Found

You want to conceal files in a directory on your webserver. Other internet boards tell you to simply move the stupid thing out of the web directory. Chances are, you would have done that obvious thing had you been able to. Let’s fix that. Find the 404 Not Found

While I do prefer to develop, any developer worth his salt is cross-trained in basic server-related tasks.
Using an .htaccess file is one of those tasks. Get your Rewrite syntax