With the "Role Manager Plugin" you can manage Roles and Capabilities of your WordPress-Blog.
Please use this plugin with care, because all changes you made, are persistent. This means: Also if you deactivate the "Role Manager Plugin" your changes stay active!
The "Role Manager" adds four pages to your blogs users menu and an additional fieldset with capabilities on a single users profile page. For using the "Role Manager" a user needs the capability "Manage Roles" additional to the "Edit Users" capability.
Also with the "Role Manager" a single user can only be a member of one role. The maximum len for a role-name is 30 chars. Only letters, digits and spaces are allowed. You can't set a role-name equal to an existing capability-name.
An "attached role" is a role with one or more assigned users.
A role with no assigned users is a "detached role".
The maximum len for a capability-name is 30 chars. Only letters, digits and spaces are allowed. You can't set a capability-name equal to an existing role-name.
If a capability is asigned to a role and no users are assigned to this role is a "detached capability".
The capability isn't assigned to any role but she is assigned to one ore more users as an extra capability.
Such a capability isn't assigned to any role or any user as an extra capability. Only this kind of capabilities can be removed if you using the button "Purge Unused Capabilities".
Places where you can find more about the System of Roles and Capabilities in WordPress: