[squid-users] Create an acl src IP with matches nothing

[Ming-Ching Tiew]

How to create an acl source IP which matches nothing ?

          acl link1 src xx

What is the xx which I need to put so that it will not match
anything ?

I tried doing xx = ! 0/0. But squid complaints that it's not valid.

Reason I want to this is that I am keeping the acl parameters
in external file, I want it to matching nothing for default,
and when needed, I change through the external file for it
to match specific IPs or subnet.

Best regards.