Until the mid-18th century, the design and significance of maritime flags flying on ships in Tunis are unknown. However, various sources have been able to distinguish certain similarities among the flags: they were designed with a crescent-oriented shape in the presence of the colors blue, green, red, and white. Thereafter, and until the early 19th century, the flag was composed of horizontal blue, red and green stripes, identifying the Ottoman regency in Tunis. This kind of flag with multiple bands and irregular contours floated on top of ships all along the coast of North Africa; similar flags with different colors and arrangements were also used on the continent.