Suppose the user request for the content such as image in www.example.com/content/img/one.jpg.
If the one.jpg is in the directory img then the image is served. But if the one.jpg is not present then user is redirected one directory up to www.example.com/content/one.jpg
.
Whether it has the requested file or not.
It must be valid for all content such as images or documents or videos etc.
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
#RewriteRule ______________________
Thanks