The "c" stands for "corrected version." The dates on the original poster (4/28-3/2) were incorrect, but the dates on the "corrected version" (3/2-4/28) were also incorrect. The actual event dates were 3/28-4/2.The dates on this poster are incorrect on both the original printing and on the "c" corrected printing. All posters in this series are diamond shaped.
