Mandatory access control list for managed content

Restricting access to managed content to users that are both members of one or more required groups identified in an ACL associated a content item to which access is requested and otherwise granted access under the ACL, e.g., by virtue of their individual identity, role, or group membership is disclosed. In some embodiments, an ACL is configured to identify one or more groups as being a "required" group, membership in which is required for a user to be granted access to a content item with which the ACL is associated. If a user is not a member of a required group, the user is denied access (or denied access above a certain level), even if the user is otherwise delegated access rights in the ACL.