# detect right proxy
        RewriteRule .* - [E=proxy:http://${pliant_config:proxy}]
        RewriteRule .* - [E=browser_key:http://${pliant_config:browser_key}]
        RewriteRule .* - [E=active_key:http://${pliant_config:active_key}]
        # cache detect:
        RewriteCond %{env:browser_key},,,%{HTTP_COOKIE}  !(.+?),,,.*SID=\1 [NC]
        RewriteCond %{env:active_key},,,%{HTTP_COOKIE}  !(.+?),,,.*SID=\1 [NC]
        RewriteCond %{env:active_key},%{QUERY_STRING} !(.+),sid=\1
        RewriteCond %{env:active_key},,,%{REQUEST_URI} !(.+),,,/_/.*\1
        RewriteCond %{QUERY_STRING} !^active 
        RewriteRule .* - [E=proxy:http://${pliant_config:cache_proxy|%{env:proxy}}]
        # cache forced:
        RewriteCond %{QUERY_STRING} ^inactive
        RewriteRule .* - [E=proxy:http://${pliant_config:cache_proxy|%{env:proxy}}]

        RewriteCond %{REQUEST_URI} ^/_/
        RewriteRule ^(.*)$ %{env:proxy}$1 [P,L,QSA]