Originally Posted By: Tirec
One of the issues being considered is wearing a colored vest or even just a name badge to denote membership on the security team.


Have you considered using a certain kind of lapel pin or tie tack? Subtle identification tokens, but obvious if somebody knew to look for them. You could even have tokens that were identical except for color: one color would denote 'security,' another color could denote 'armed,' etc...
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(posting this as someone that has unintentionally done a bunch of stupid stuff in the past and will again...)