Is it possible to check for X and (Y or Z) with mod_rewrite?
I have the following rule to serve dummy.png to guests of my website, who don't have 2 cookies id and auth set (I set those in my custom Drupal module for registered users):
RewriteCond %{REQUEST_URI} ^/sites/default/files/pictures/picture-
RewriteCond %{HTTP_COOKIE} !auth [OR]
RewriteCond %{HTTP_COOKIE} !id
RewriteRule .+ /images/dummy.png [L]
but I'm not sure if it works as intended (maybe it acts as (X and Y) or Z instead?)