Epifind - Access Control List

Hi, 

I have a few questions about epifind and access control.

While showing search results, we have to limit access to certain users / groups. In the documentation (http://find.episerver.com/Documentation/episerver-cms-integration-access-rights), there is a method "RolesWithReadAccess" to filter out users / groups.

• what is the logic behind this method "RolesWithReadAccess" ? If I use this method like RolesWithReadAccess("Everyone") what does it mean for that group "Everyone"? and what does it mean to other groups on the website.
• If new groups are created in AD and used by the editors to access control pages ( we are using Epinova to import AD groups into Episerver website), do we have to create a new method RolesWithReadAccess ? or is there way to automatically add newly created groups to filter like "all groups"

Thanks.