A plain red flag with a golden hammer and sickle and a gold-bordered red star in its upper canton and an horizontal blue band on the bottom fourth.
The flag of the Azerbaijan Soviet Socialist Republic was a plain red flag with a golden hammer and sickle and a gold-bordered red star in its upper canton and an horizontal blue band on the bottom fourth.
The national flag of Azerbaijan Soviet Socialist Republic is a panel consisting of two horizontal bands of color: the upper red part of three quarters of the width and the bottom is blue, nearly one quarter the width of the flag with the image on the top left corner of the red band, at the flagpole and gold hammer and sickle, and above them a red five-pointed star framed by gold fringe. The ratio of width to length is 1:2.
The text of national flag in the Constitution of the Azerbaijan SSR was updated on August 18, 1953. However the text didn't specify the proportion of the hammer and sickle. On May 5, 1956, the Presidium of the Supreme Soviet of Azerbaijan SSR approved the "Regulations on the State flag of the Azerbaijan Soviet Socialist Republic", which further regulated the details of the elements on the flag. On March 16, 1981, the Presidium of the Supreme Soviet of Azerbaijan SSR further issued a decree specify that no hammer and sickle should be printed on the reverse side of the flag.
From the second part of 1921 to 1922, Azerbaijan SSR used a red flag with the yellow Cyrillic characters АССР (ASSR). On March 12, 1920, the Azerbaijan SSR united with the Georgian SSR and the Armenian SSR under the Transcaucasian SFSR (TSFSR), that was split again into these three republics in 1936.
In 1937, golden hammer and sickle were added in the top left hand corner, with beneath the Latin characters AzSSR in a serif font in place of the Cyrillic characters. A third version was issued in 1940s, and had AzSSR substituted by its Cyrillic version АзССР.
^Конституция (Основной Закон) Азербайджанской Советской Социалистической Республики, принятая 21 апреля 1978 года внеочередной сессией Верховного Совета Азербайджанской ССР. — Баку, изд-во Верховного Совета Азербайджанской ССР, 1978, С.19