See the note lower left above the numbers.... Confirms that for drones only 1 number is needed, not a unique number for each drone. FAA really just wants to be able to find you.
Hobby/Recreational ~ 1 Registration # (operator is registered not aircraft) and the same one can go on ALL of your hobby aircraft
Commercial/P107/Public Use ~ 1 unique FAA registration # per aircraft. Each aircraft is registered.