Long call is basically voluntary starting January 1.
No one ever has to acknowledge a trip until three hours prior to report and that means you cannot fly that trip. You can choose to acknowledge more than 10 hours prior if you wish, but no one is required to do so. It's strictly voluntary.
Management cannot rewrite our contract by issuing memos. If they want to clarify or change the long call provisions contained in our contract then they must either negotiate with ALPA or dock somebody's paycheck and force a grievance.
Until then they will just have to cover their open time using short call reserves, white slips and green slips.