Linking contacts is the combining of the same contact from multiple
services into one Contacts entry. This feature helps you keep your address
book organized, with all details about one contact in one place.
Select the contact you wish to link in the left pane.
Right-click on any editable element in the right pane and select
Add/Remove Linked Contacts….
Select the entry you wish to link with the first contact entry.
If you wish to link a third contact entry, repeat the last two steps.
When you are finished, click Close.
If you linked two contacts accidentally and want to undo the action, follow
the steps for unlinking contacts.