$_SERVER[‘HTTP_IF_MODIFIED_SINCE’] отсутствует
В случае если, $_SERVER[‘HTTP_IF_MODIFIED_SINCE’] отсутствует:
.htaccess
RewriteEngine on RewriteRule .* - [E=HTTP_IF_MODIFIED_SINCE:%{HTTP:If-Modified-Since}] RewriteRule .* - [E=HTTP_IF_NONE_MATCH:%{HTTP:If-None-Match}]
php:
session_cache_limiter('private_no_expire'); session_start();