If the contact is a bot.
Is the contact a key contact.
True if the contact can be added to protected chats because SELF and contact have verified their fingerprints in both directions.
See [Self::verifier_id]/Contact.verifierId for a guidance how to display these information.
the contact's last seen timestamp
The contact ID that verified a contact.
As verifier may be unknown,
use [Self::is_verified]/Contact.isVerified to check if a contact can be added to a protected chat.
UI should display the information in the contact's profile as follows:
If verifierId != 0,
display text "Introduced by ..."
with the name and address of the contact
formatted by name_and_addr/nameAndAddr.
Prefix the text by a green checkmark.
If verifierId == 0 and isVerified != 0,
display "Introduced" prefixed by a green checkmark.
if verifierId == 0 and isVerified == 0,
display nothing
This contains the contact ID of the verifier.
If it is DC_CONTACT_ID_SELF, we verified the contact ourself.
If it is None/Null, we don't have verifier information or
the contact is not verified.
Is encryption available for this contact.
This can only be true for key-contacts. However, it is possible to have a key-contact for which encryption is not available because we don't have a key yet, e.g. if we just scanned the fingerprint from a QR code.