About transparent proxy you can reading here
http://en.wikipedia.org/wiki/Proxy_server#Transparent_proxySince release HandyCache RC2 1.0.0.103 UNSTABLE, HC can't do forward nat port a router anymore and just work perfectly from pointing browser to ip/port handycache, and it's very distressing when a network using a router like mikrotik .
in Indonesia most of the internet cafe to use the router for the network and an average of 10 clients to 40 clients
I know for handycache freeware is limited to 5 users only, but now why cannot forward from nat router anymore?
if this security issue we can manage through a router or firewall in windows.
I know handycache do block forward port 80 with a silent response
because the result only blank white browser
cmiiw
hope (mai62) on the upcoming release handycache want to open again for the forward of nat router
*sorry i just using google translate