The Formal Dress variation is the most formal, and is identical to the Dinner Dress Blue Jacket uniform but worn with a white waistcoat with gold buttons in place of the cummerbund, a white bow tie, and matching mother-of-pearl studs and cuff links. Though rarely used, men can also substitute a tailcoat for the standard dinner dress jacket with this uniform. The female version is substantially the same as Dinner Dress Blue Jacket, but substitutes the mother-of-pearl studs and cuff links for gold. This uniform is equivalent to white tie in usage. Additionally, this uniform is only prescribed for chiefs and officers.