What is "opt-in"? October 22, 2021 11:38 Updated "Opt-in" is an application for CMS:XEM holders to show a "statement of intent" to receive the new CMS:XYM currency. Related articles What is the Airdrop? What is the "opt-in" application period? How to apply for "opt-in" What is the necessary to apply for "opt-in"? Schedules