Registred (verb)
simple past tense and past participle of registre
Registered (verb)
simple past tense and past participle of register
Registered (adjective)
Having had one’s name added to an official list or entered into a register
“a registered nurse”
“a registered voter”
Registered (adjective)
Having a mailed item recorded in a register to enable its location to be tracked, sometimes with added insurance to cover loss.
Wiktionary
Registered (adjective)
entered or recorded on an official list or directory
“a registered charity”
Registered (adjective)
(of a letter or parcel) sent by registered post
“we have sent registered letters to all her addresses but there has been no response”
Oxford Dictionary