Unlockable Contacts, as the name implies, are contacts that you have to unlock in order to obtain missions. After they are unlocked, they will assign you missions and sell you enhancements and inspirations. At present, unlockable contacts only appear in the Rogue Isles. The only method to unlock them are through obtaining various badges and being in a required level range. It is possible to outlevel them and not be able to complete their missions.