I looked at the registration in the past. YOU register. Not once on any form or web page did it request any specific aircraft data such as make, type, weight, etc. The only info it requested was YOUR information. Name, address, etc. I did register, however out of stubbornness, I didn't mark but one drone and that wasn't printed in standard alphabet symbols so unless the cop or whoever has played
commander keen, he isn't reading it. But it is marked No requirement was stated that it must be marked using A-Z symbols. The code is there. Its distinguishable from the background therefore satisfies the "legible" requirement.
During the registration process, not once did it inquire as to what uAV I owned or would be flying. Technically you had to register if you were going to fly any drone. Even one you don't own. Just like a driver's license allows you to operate any motor vehicle of your license class, whether you own it or not.
Also please READ the PDF that YOU linked:
https://www.faa.gov/uas/getting_started/fly_for_fun/media/UAS_how_to_label_Infographic.pdf
Under the red/gray blow up, what does it say?
All your aircraft get marked with your number. Not their unique number because each one doesn't get a unique number. Each registered pilot does.
The point is moot anyway.
Registration Deletion
Fly for Fun under the Special Rule for Model Aircraft
...