What constitutes official business during crew rest?

Official business during crew rest primarily involves activities that are essential for the safe conduct of an upcoming flight, while ensuring that the crew remains rested and ready for duty. Digital communications with aircrew that relate to flight operations, coordination, or urgent updates qualify as official business. This type of communication is often necessary to align the crew’s understanding and prepare for upcoming operational requirements.

Other activities listed, such as flight planning activities, reviewing flight manuals, and pre-flight checklist reviews, can be seen as more intensive forms of preparation or study that might detract from a crew member's ability to rest adequately. While they are important tasks, they may not be classified as immediate official business during the designated rest period, which is aimed at ensuring optimal performance through adequate rest.