Funny, but I didn't see any similar notices at the Eventing in Greenwich Park today. We all pretty much knew who was doing the encouraging and who the jumping. The crops were a dead giveaway.
Actually, I could see how the jacket would be useful for those dark nights on unlit country lanes when you have to gallop off on the horse for some unknown reason (can't think of one right now) and only the jacket is visible.
(I should think it would probably totally spook anyone who met it under those circumstances.)
(I should think it would probably totally spook anyone who met it under those circumstances.)