Which property is a UID for both an ABRecord and AB Property?

Question

I'm trying to figure out which property values I can rely on to store a reference to an address book contact and phone number, to avoid the potential for records to randomly change in my app. I believe I've figured out that the ABMultiValueIdentifier is the UID for an entry in a multi-value property (since it needs to be translated into an index to be accurate), but I'm not sure when it comes to identifying address book records and properties themselves.

For the address book record, is it the ABRecordRef or a combination of ABRecordID + ABAddressBookRef (or are both just as reliable)?

For the address book record property (multi-value and otherwise), is it the ABPropertyID?