Inheritance of Permissions
Inheritance of permissions is similar to inheritance of properties. If the parent has a permission, then the child inherits that permission.
For example, if Bob belongs to GroupA, and GroupA has publish permission on a topic, then Bob has publish permission on that topic.
Permissions for a single user are the union of the permissions set for that user, and of all permissions set for every group in which the user is a member. These permission sets are additive. Permissions have positive boolean inheritance. Once a permission right has been granted through inheritance, it can not be removed.
All rules for wildcards apply to inheritance of permissions. For example, if a user has permission to publish on topic foo.*, the user also has permission to publish on foo.bar and foo.new.
For more information on wildcards, refer to Wildcards. For more information on permissions, refer to User Permissions.