Since you asked: Horsehair sporrans, spats, feather bonnets and long plaids label the wearer a wannabe piper/drummer. It's a bit like wearing medals/rank badges you haven't earned. Dirks are for killing people. Wish I got invited to a few more white tie funtions so I could justify the cost of a montrose jacket and jabot. Tartan waistcoats and ties are a good way of demonstrating your heritage/affiliation when you have to wear trousers;They should never be worn with the kilt. In a day or evening formal setting dress according to tradition ( not history! ). In a casual setting almost anything goes except for baseball caps, which should be reserved for your inevitable audience with Satan should you transgress. It is of course your human right to dress as tastelessly as you wish. Now, who will bite?