Group rights

["Joyce, Matthew" <MJoyce@ccia.org.au>]

Dear Debain Users,

I'm a little confused regarding the use of group to assign file rights.

I was under the impression that user can be members of groups and groups can
be used to assign permissions to files and folders.

How then, do I assign multiple groups, different permission to the same
folders and do those permissions cascade downwards ?
If they do, how do you stop them ?

Do I have to make a new group (GroupAandGroupB) and manage it that way ?

I'm thinking along the lines of Novells (rather good) Trustee
Rights/Inherited Rights/Rights Masks.

Can groups be members of groups ?

Thanks

Matt