A: The phrase on the banner above the flag, "Say Au Revoir But Not Good-Bye," is the title of music written by Harry Kennedy in 1893. It was revised by E.T. Paull in 1918 during World War I. The handkerchief was a souvenir made about 1917 to 1919. The official American flag had 48 stars on it at that time. The 17 stars on the flag in the background may have been a design decision. Souvenir handkerchiefs sell for $20 to $25.