The uniforms of the United States Navy include dress uniforms, daily service uniforms, working uniforms, and uniforms for special situations, which have varied throughout the history of the navy. For simplicity in this article, officers refers to both commissioned officers and warrant officers. Dress uniforms The United States Navy has three categories of dress uniforms, from least to most formal: service, full, and dinner dress. Service dress Service dress uniforms are worn for official functions not rising to the level of full or dinner dress. They are also commonly worn when traveling in official capacity, or when reporting to a command. The civilian equivalent is a business suit. Service Dress Blue may be worn year-round, while Service Dress White is reserved for summer or tropical zones. Ribbons are worn over the left breast pocket in all variations of the service dress uniform. An all-weather overcoat or reefer coat may be worn with service dress uniforms in cold or inclement weather. Officers and chief petty officers Service Dress Blue The Service Dress Blue (SDB) uniform consists of a dark navy blue suit coat and trousers (or optional skirt for women) that are nearly black in color, a white shirt, and a black four-in-hand necktie for men or a neck tab for women. The material is generally wool or a wool blend, depending on the vendor. The men's jacket is double-breasted with six gold-colored buttons, and the women's jacket single breasted with a single row of four gold-colored buttons. Rank insignia are gold sleeve stripes for commissioned officers, while rating badges and service stripes are worn on the left sleeve by chief petty officers (CPOs). The prescribed headgear is a white combination cap, although a navy blue garrison cap is optional in some situations when the jacket is not worn, unless stated otherwise by the prescribing authority. Beginning in 2016, the Navy began phasing out the distinct female combination cap and now prescribes a cover similar to the male version for female officers and CPOs; the prior female versions were authorized for wear until October 2018. Commissioned and warrant officers above grade W-2 wear a cap badge of the U.S. shield and eagle in silver upon gold crossed anchors, warrant officers at grade W-1 a pair of crossed anchors, while CPOs wear a single fouled anchor. The combination cover's chinstrap is gold for commissioned and warrant officers, narrower gold for midshipmen and