What is a key rule regarding the sterile cockpit while taxiing?

The key rule regarding the sterile cockpit while taxiing emphasizes the need for undistracted focus on the aircraft's operation. This rule is particularly important during critical phases of flight, such as taxiing, takeoff, and landing. The prohibition against looking at text messages aligns with this principle because engaging with electronic devices can divert attention from vital tasks related to flying the aircraft.

By avoiding distractions like text messages, flight crew members can maintain a higher level of situational awareness, ensuring the safety of the flight and responsiveness to the environment around them. This focus is crucial in managing the complexities that may arise during taxiing, such as traffic and runway intersections. Prioritizing attention to cockpit operations over personal electronics embodies the sterile cockpit rule's intent to minimize distractions.