In the RAF mess dress, officially designated Number 5 dress, is worn at formal evening functions. All regular officers, Warrant Officers and Senior NCOs possess mess dress. The current mess dress for men consists of a high waisted blue-grey single-breasted jacket fastened at the front by a single link of two RAF buttons connected by a link clip, white marcella shirt, bow tie, waistcoat or cummerbund and blue-grey trousers. Rank, for officers, is indicated in gold braid on the lower sleeve.