<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType application/javascript "access 1 week"
ExpiresByType text/css "access 1 week"
</IfModule>
I use a lot of these in my .htaccess files to set caching, deflate, Accept-encoding headers and stuff. I have noticed that if I delete the open and close tags, everything keeps working. What do these do, and is it safe to delete them, as long as everything seems to be working right?