When traveling by commercial passenger aircraft, couriers must do what to obtain priority service?

To obtain priority service when traveling by commercial passenger aircraft, couriers must identify and present themselves to airline ticketing and screening officials. This process is crucial because it allows airline personnel to recognize the couriers as part of an official mission, which can help facilitate expedited check-in, screening, and boarding. Establishing this identification ensures that the couriers receive the necessary support and accommodations that align with their responsibilities as part of the Department of Defense's logistics and transportation operations.

The other options, while they may seem relevant, do not effectively ensure priority service. Requesting a first-class ticket does not automatically provide the priority status needed for couriers, as it does not inform airline officials of their specific roles and requirements. Using hidden identification would not be advisable or effective, as transparency is essential in official transportation to maintain security and protocol. Lastly, wearing a military uniform may provide some recognition but does not replace the importance of formally identifying oneself to the airline staff, which is a critical step to ensure that couriers receive the priority services they need during their travel.