What is "yank!"

Yank! A WWII Love Story is a 2005 musical with book and lyrics by David Zellnik and music by his brother Joseph. Yank! "tells the story of Stu, a scared Midwestern kid who gets drafted for World War II in 1943, and becomes a photographer for Yank Magazine, the journal 'for and by the servicemen.' Yank! has a score that pays homage to the 1940s and explores what it means to be a man, and what it is to fall in love and struggle." Yank! takes its title from the World War II publication Yank, the Army Weekly.