Once a contact is entered with a PIN number BBM will be the preferred messaging route to that person. There are lots of PIN sharing forums here at CB. Pick a group you like and let the sharing begin.
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When you go to your phone book and edit or add a person if you scroll down there is a slow named PIN, if you go to the options menu then go to status it shows your pin, if you want to add somebody get their pin add it to the slot then go to your bbm and go to add contact, then select the contact from the list it provides you, you can't really add contacts to your bbm unless you have their PIN
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