<Transmittal Root> and Its Components
Every valid transmittal must contain exactly 1 <Transmittal Root> object, which is the ‘root object’ of the transmittal - the root of the object tree.
Every object in a correctly produced transmittal is connected by aggregate-component relationships, either directly or transitively, with the <Transmittal Root> of that transmittal.
Consequently, the <Libraries> and <Environment Roots> are components of the <Transmittal Root> - the organizer of organizers.