According to JSP 336 (3rd Edition) Vol. 12 Pt. 3 Pamphlet 13 Section 3 Appendix 1 to Annex G to Section 3 SSIs and AIs are required to wear brassards. Never heard this before, but just read it at that link. Maybe ive read it wrong, it is half 2 in the morning, but i think dats wat it says.