Eh...as several other guys around here are, I grew up around martial arts. My daily routine during the school year was basically: Morning football or wrestling practice, school, afternoon practice, then to the dojo.
Never heard of ANYONE having to "register their hands...". I flat out asked one of my instructors when I was a teenager and this rumour was going around and his response was "No....that is a myth".
When I became a police officer I looked through the PC to find anything that might allude to this being a truth and found that it is a bunch of BS.
So, I say "Show me a guy that registered his hands as lethal weaopns, and I will show you someone with dementia".
I guess they could be "registered" as 5150.