This built-in role has been preset to give you full access to the system’s functional areas, so that you could add users and roles as you see fit, do some ’fine-tuning’ such as by adding custom fields to projects or activities, or editing available activity categories, statuses, etc.
Unlike all other roles, preset or created by you, the Administrator role has no place among a project member’s roles. This is done by leaving all project member-related permissions in this role undefined. In practice, when an Administrator-role user creates a new project s/he is automatically assigned the Project Manager role. Similarly, when a project member is assigned a role on a project, the Administrator role is not up for selection.