In our app we keep references to contacts in the address book. What is the best way to make sure that we can deal with updates (both from our app to the address book as well as from the address book to our app).
We want to make sure we can handle spelling mistakes, address phone and email changes, synchronization, duplication, 'interesting' use of first last and company name etc.
Currently we check first on addressbook id. Only if it changes, we update our information/try to find back the contact. This is not good enough.