[Squid external acl scheme - Guidelines]

Guidelines

External helpers

It should use external helpers to query if the ACL matches or not

Flexible

It should be possible to base the ACL on a number of criterias such as login, ident, client IP, ...

More than one

There is need to allow for more than one set of helpers. Different ACL's have different requirements

Multiple ACL's sharing the same helper set

to allow ACL's that are similar but not fully identical to share the same set of helpers. For example LDAP group ACL's in the same LDAP server.