http://jptvwdeyknkv6oiwjtr2kxzehfnmcujl7rf7vytaikmwlvze773uiyyd.onion?page=705750674770450706308
Put simply, a v3 onion address is (1) a 32-byte (not bit) public
key, (2) a checksum, and (3) a version all encoded together (in that order) in
base32. The version is always 3 (or 'd' in base32), thus they always end in
'd'. For more information, see the v3 onion spec .
This links directly to the right section as of the time of writing.