olemus
a letter, the address of which is, on payment of a special fee, registered in the post office and the transmission and delivery of which are attended to with particular care

Eestis: vt tähtsaadetis

ülevaateid
https://www.lawinsider.com/dictionary/registered-letter

https://en.wikipedia.org/wiki/Registered_mail

https://blog.eevidence.com/en/what-is-a-registered-email/

vt ka
- tähtsaadetis