What does International Z1 mean in some of the Combo plans? International Z1 means you can now use selected combo plans to make international calls to countries in Zone 1 (Australia + South Pacific countries) if you do buy these plans. For more information about this, email us on CustomerCarePNG@digicelgroup.com. You can also chat live with us. Digicel's Terms & Conditions Apply. Related articles Will I also be able to call other networks if I buy the new combo plans? What are the Digicel 1TOK Combo+ Plans? What countries can I use my International Voice Bundle to call? International Voice Bundle (IVB) What are the 'Double Data' Plans?