Is RecordID always unique?

[micnguyen]

I have noticed that when I delete a contact from the address book and then adding another contact, that it doesn't overwrite the removed ID and instead adds a new one. Is the recordID for an APContact always unique? I'm trying to sync up a custom domain model to an APContact sych that each APContact represents a 1:1 custom model and am using recordID. Is the record ID similar to that of Identifier in https://developer.apple.com/documentation/contacts/cncontact/identifier?

[belkevich]

I don't think that recordID matches Identifier. APAddressBook is a wrapper on deprecated AddressBook.framework not Contacts.framework.

[belkevich]

But if you try, please, tell us your results