In Caster, in order to provide access to users of Play MPE you have to specify which recipient lists are allowed to receive your emails and view your releases in their players. Contacts are simply groups of recipients, emails and contact information as organized by someone with list manager privileges. 

Each label can create and manage their own contacts for their use only. In addition, all labels have access to lists provided and curated by Play MPE.  

When you sign in and access the contacts section in the main menu, you will see every list available to your label along with controls to create, edit, import, export and lists and individual recipients. Every list can be organized within folders, named, copied and moved to match your own organization needs.