该选项导致squid的忽略请求里的任何no-cache指令
如果希望内容一旦进入cache就不删除，除非是被主动purge掉为止，可以加上ignore-reload 选项，该项常用在mp3，wma，wmv，gif 之类
如
refresh_pattern -i \.mp3$ 1440 50% 2880 ignore-reload
refresh_pattern -i \.wmv$ 1440 50% 2880 ignore-reload
refresh_pattern -i \.rm$ 1440 50% 2880 ignore-reload
refresh_pattern -i \.swf$ 1440 50% 2880 ignore-reload
refresh_pattern -i \.mpeg$ 1440 50% 2880 ignore-reload
refresh_pattern -i \.wma$ 1440 50% 2880 ignore-reload
5 Ignore-no-cache
该项导致squid强制忽略从源站而来的“Pragma：no-cache”和“cache-control：no-cache”
6 Ignore-private
该项导致squid强制忽略从源站而来的“cache-control：private”
7 Ignore-auth
该项导致squid 强制将一个请求认为是源站发送的带有“cache-control：public”
8 Ignore-no-store
该指令是忽略来自源站不缓存对象
a no-store directive from the Web server which makes an object non-cacheable is ignored.
9 Refresh-ims
该项是client一个刷新请求转换成一个If-Modified-Since 请求
a refresh request from a client is converted into an If-Modified-Since request.