ISO 3166-2:BG ISO 3166-2:BG ISO 3166-2:BG is the entry for Bulgaria in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions (e.g., provinces or states) of all countries coded in ISO 3166-1. Currently for Bulgaria, ISO 3166-2 codes are defined for 28 districts. Each code consists of two parts, separated by a hyphen. The first part is , the ISO 3166-1 alpha-2 code of Bulgaria. The second part is two digits (01–28). The codes are assigned in Bulgarian alphabetical order. Subdivision names are listed as
Great Lakes BG of the open cockpits of the prototype. A total of 61 of these aircraft were built, including the prototype. The BG-1 entered service in October 1934, equipping VB-3B (later re-designated VB-4) aboard the carriers and . It was also operated by the Marine Corps, equipping two squadrons from 1935. The BG-1 continued in front line use with the Navy until 1938, and with the Marines Corps until 1940. It was used for utility duties at shore bases until June 1941. Great Lakes BG The Great Lakes BG was an American carrier-based dive bomber of the 1930s. Designed and built by