What should the Referee do if Fencer X arrives at the bout without a safety strap on their mask?

In this scenario, the proper course of action for a referee is to award a yellow card and require the fencer to put on a safety strap before continuing the bout. The safety strap is crucial for ensuring the fencer's mask remains secure during competition, thereby protecting them from potential injury.

By issuing a yellow card, the referee communicates the seriousness of the infraction while still allowing the fencer an opportunity to rectify the situation. The yellow card serves as a warning and emphasizes the importance of safety equipment in the sport, reinforcing the rules meant to protect athletes.

Continuing the bout without addressing the missing safety strap would compromise the fencer's safety, while issuing a red card immediately would be excessive for this type of infraction, as it typically indicates a more serious violation of the rules.