warrant officers 1, and black for CPOs. Females typically wear beltless slacks with the SDB, although since January 2017, belted slacks can be worn as an alternative. Service Dress White The Service Dress White uniform was different for men and women until 2017. Men wear a high stand-collared white tunic, with shoulder boards for officers or metal anchor collar devices for CPOs, white trousers, and white shoes. This uniform is informally called "chokers" due to the standing collar. The material, formerly cotton, today is a weave of polyester known as "Certified Navy Twill". The white combination cap is the prescribed headgear. Women previously wore a uniform similar to the Service Dress Blue uniform but with a white coat and skirt or trousers. Officer's rank insignia consisted of lacing on the sleeves in the same manner as on the blue uniform, while CPOs wore rank insignia pins on the lapels of the jacket. However, women's uniforms were changed to resemble men's uniforms: female officers and CPOs began wearing stand-collared tunics similar to the male uniform in early 2017, with full replacement of the old-style uniform by the end of January 2020. Junior enlisted sailors Service Dress Blues for male junior enlisted sailors are based on the classic sailor suit in navy blue, colloquially referred to as "crackerjacks" because of the sailor-suited figure that adorns the packaging of Cracker Jack snacks. It consists of a navy blue wool pullover jumper with an elongated "tar-flap" collar adorned with three rows of white stripes and two white stars, one at each corner of the collar. The jumper's cuffs are similarly adorned with white stripes. A black silk or synthetic fiber neckerchief, rolled diagonally, is worn around the neck, under the collar, with the ends tied in a square knot in the center of the chest. The trousers for the uniform are flared as "bell bottoms". The trousers have traditionally featured a broad-fall opening, though changes to the trousers announced in 2012 have added a zippered fly, rendering the buttons merely decorative. A traditional white "Dixie cup" hat is also worn, as well as black leather shoes. For a brief period in the 1970s and early 1980s, male enlisted sailors in paygrades E-1 to E-6 wore a double-breasted blue uniform based on the version worn by officers and CPOs, but with grey buttons and a combination cover with an emblem consisting of a silver eagle