The design of the Commonwealth flag reflects the close ties that bound the Cuban and Puerto Rico patriots in the 19th century for the flag which waves over the Capital of San Juan is the Cuban flag color reversed.
The Puerto Rican flag consists of 5 alternate red and white stripes. On the left of the flag is a single white five-pointed star resting in a blue triangle. The symbolism is explained thus. The white star stands for the Commonwealth of Puerto Rico while the three sides of the equilateral triangle together represent the three branches of the Republican government (executive, legislative and judicial branches). The three red strips symbolize the blood that feeds those parts of the government. The two white stripes symbolizing the rights of man and the freedom of the individual, are a perpetual reminder of the need for vigilance of a democratic government is to be preserved.
The flag is not flown except in company of the U.S. flag. Adopted in July 25, 1952.