Developers, Uploaders, and Account Owners may find it useful to store contacts in this feature. 

You can add or remove contacts from the tab on your profile. 

Uploaders and Developers may still add Reviewers and Developers by pasting in email addresses (separated by commas) but they may be typed in to pull from the address book. 

When you add a new email address to a course as a Reviewer or Developer that user will also be added to your contacts list. 

Note: The contact's name is created/edited by the contact in their profile page. Sometimes this means that Reviewers may not have a name (because some Reviewers never login).