My CodeIgniter .htaccess

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /PROJECT_PATH
#Removes access to the system folder by users.
#Additionally this will allow you to create a System.php controller,
#previously this would not have been possible.
#'system' can be replaced if you have renamed your system folder.
RewriteCond %{REQUEST_URI} ^system.*
RewriteRule ^(.*)$ index.php/$1 [L]

#Checks to see if the user is attempting to access a valid file,
#such as an image or css document, if this isn't true it sends the
#request to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
#This last condition enables access to the images and css folders, and the robots.txt file
#Submitted by Michael Radlmaier (mradlmaier)
RewriteCond $1 !^(index\.php|images|robots\.txt|css)
RewriteRule ^(.*)$ index.php/$1 [L]
</IfModule>