appointments, may optionally wear instead a long-sleeved, high-necked white tunic, with five buttons down the front, worn with white trousers and white shoes. Other officers may be instructed to wear this uniform "when required to conform with accepted international standards of dress on state or major ceremonial occasions". There is also a white version of No. 2 dress; gold-laced navy blue trousers may be optionally worn with white No. 2 dress by officers of the rank of captain and above. White No. 3 dress is the same as 3B dress, but is worn with white trousers, socks, and shoes in place of the black versions normally worn. White number 3B and 3C uniforms have been abolished. They consisted of a white short sleeve shirt and white shorts; 3B was worn with long white socks and white shoes, while 3C was worn with boat shoes. Both white 3B and white 3C dress have been replaced by the new number 4 RNPCS dress. Senior ratings No. 1 dress For senior rates, petty officer and above, No. 1 Dress consists of a double-breasted jacket similar to that worn by commissioned officers but with only six buttons. Historically, this was originally known as the 'long jacket', and was first introduced for engine room artificers, masters-at-arms, and schoolmasters. Later, its use was extended to all Chief Petty Officers (1879) and Petty Officers (1920). Relevant rate insignia is worn on the left arm of the jacket by petty officers. Like their counterparts as worn by commissioned officers, it is divided into 1A, 1B and 1C dress. In 1A dress, when armed, a white web belt and white gaiters are worn by senior ratings as they are by junior ratings. WO1s wear a sword and sword belt with 1A dress. However this differs from that worn by commissioned officers in that it has a black grip instead of a white one, and it has a plain stepped pommel instead of the officers' lion mane one. No. 2 dress This mess undress is optional wear in the evenings for dining by all senior rates and warrant officers. It is worn with a black cummerbund and miniature medals. The cut of the jacket is different from that worn by officers: it is double breasted, but features a shawl collar and only four buttons instead of six. Trade badges and other non-substantive badges are not worn on the mess jacket,