Whether you agree with the FAA’s requirement to register your drone if it weighs more than 0.55 pounds (250 grams) so you can fly it outdoors for fun as a hobby this is now the law as of 12/21/2015.
I would rather ensure my drones are registered rather than face the possibility of a civil penalty up to $27,500. I know I won’t be using them for any criminal activity so I will definitely not face the prospect of fines up to $250,000 and/or imprisonment for up to three years. You can view the full rule here www.faa.gov/news/updates/media/20151213_IFR.pdf
When registering you complete the form with your name, home address, email address, etc. and you will be issued with a unique registration number, you can also use your drone’s serial number when registering. The problem I foresee with using the serial number is if you change drones you have to go through the process of registration once again. If you are issued with the FAA unique registration number it covers any drones you have. You can click HERE to go to the FAA website to register your drone/UAS
Drones/UAS have to be marked with your registration number and this can be done using labels, engraving or using a permanent marker and the number must be readily accessible, readable and legible for visual inspection. You may put the registration number in your battery compartment if you don’t want a visible number on external areas of the drone.
If you would like professionally produced labels for your drone as one way of complying with the FAA regulations then go to Drone Registration Label who can provide them for you.