If you use the Synchronization Tool for syncing contacts between MS OutlookTM then your account will have "Private" Contacts that only the Account Logged in user can see. That may be fine for a single user environment, but if you have a Team - you may want to share your "Private" Contacts by making them "Public" Contacts.
NOTE: A "Public" Contact simply means other authorized users of your account can see the details of that record. It does not mean anyone can see the account - only authorized users in the account.
To change Private Contacts to become Public contacts:
1. Preform an Advanced Search for all of the Private Contacts, choose the field "Private Contacts" and select "Yes."
2. Click, "Search" to net the results of a search.
3. Using the checkboxes, check the records you would like to convert to Public. At the bottom of the screen locate a button titled "Update Value"
4. Choose Update Value and select update "Private -> Public"
5. Click Submit and notice the Changes within the Contacts tab.
See the Figures Below to further demonstrate the process.