The origin of the phrase Jolly Roger is unclear, and many explanations have been proposed to explain it. However, it seems that the correct answer is that it is a variation of “Old Roger“, the original name of the flag. In the English language, the word “Old Roger” refers to the Devil. As a final detail, add that after Jack Rackham’s death, Anne Bonny received all of his possessions, including his ship and flag, and that he altered the design of the flag by replacing one of the swords with a rifle, in honor of his friend Mary Read.