[squid-users] Questions about acls

Hi,

I've some questions about three squid acl.

1- myip
Does this acl specify incoming traffic (the interface that receives
client requests) or
outgoing traffic (interface that inoltrate client requests to the net)?
Furthermore, how does it work with multple interface?
May I use this to block/permit all the traffic of one interface?

2- maxconn
Is this acl independent form the others?
If I have an acl list like the following:

acl pippo src 192.168.1.10
acl limit maxconn 2

http access allow pippo
http access deny pippo limit

how many connections pippo can use? 2 or infinite?

In addition, if I specify more that one maxconn acl, which one will prevail?

3 - proxy_auth
How this acl work? does squid check every time for auth, or just one time?
Can be used with other acl in the same htpp_access rule? what are its
relations
with the ident acl?

Thanks in advance,
regards

Alberto