Contacts come from multiple sources called Accounts. You can have contacts stored on for example your iCloud Account or Exchange Account. Cardbox is also an Account, which is set up on your phone when you install the configuration profile. Lastly, there is a separate Account for contacts saved locally your device.
To provide the best user experience, iOS combines the contact information of the same person from all Accounts into a single Unified Contact. When you view a Unified Contact in the Contacts app, you can scroll all the way to the bottom and view the separate linked contacts from each Account by tapping them.
When you connect with someone on Cardbox, we add them as a contact in your Cardbox Account. Since everyone on Cardbox gets control over their own contact information, contacts in the Cardbox Account are read-only, and we update them for you when a connection makes changes to their card.
We address all contacts from Accounts other than Cardbox as Legacy Contacts, since these are not automatically managed by Cardbox, but managed manually by yourself.
To ensure that Unified Contacts only contain Cardbox contact information, and not duplicate or outdated contact information from other sources, we suggest you to remove all Legacy Contacts of a person after you connect with them on Cardbox (unless Legacy Contacts contain important information that is not provided by Cardbox).