Which of the following is NOT a reason to refrain from serving alcohol to a passenger?

Serving alcohol to passengers in an aviation context requires careful consideration of their safety and compliance with regulations. The reason for not serving alcohol to a passenger wearing a uniform is that wearing a uniform does not inherently indicate any impairment or rule violation. Uniformed individuals, such as crew members, may have responsibilities and protocols concerning alcohol consumption that are different from those of regular passengers.

On the other hand, the other scenarios represent clear and justifiable reasons to refrain from serving alcohol. For example, if a passenger appears intoxicated, serving them alcohol poses safety risks and could exacerbate their condition. Similarly, serving alcohol to individuals who are underage is against the law and could result in severe legal repercussions for the airline. A passenger boarding as a flight deck jump seater has established regulations around alcohol consumption that must be adhered to, including not consuming alcohol during the flight or before its operation.

Thus, the stipulation concerning individuals wearing a uniform is not a valid reason to refuse service, as their attire alone does not indicate any need for caution regarding alcohol service.