Which of the following is not a permissible action in uniform regarding behavior at events?

Participating in a political demonstration is not a permissible action in uniform due to regulations that govern military personnel's engagement in political activities. The authorities recognize that military service members should maintain a nonpartisan appearance and demeanor while in uniform to uphold the integrity and objectivity of the military. Involvement in political demonstrations could imply an official stance on political matters, which is contrary to the expectations of neutrality expected from service members.

On the other hand, attending charity events, engaging in community service, and observing cultural festivals are generally acceptable because these activities support community relations and foster goodwill without implying a political affiliation. Thus, these actions align with the military’s commitment to serving the public and contributing positively to society while still maintaining the required decorum and professionalism associated with military service.