The reverse of a 1945 'Jumbo Post Card' from San Antonio, Texas, bears a wartime security reminder: 'The ENEMY is listening—Don't SAY it. The ENEMY can READ—Don't WRITE it.' Paired with the 'Keep 'Em Flying in Combat Teams' emblem honoring bomber crew roles, this card reflects the pervasive wartime culture of operational secrecy that touched even everyday souvenirs sold to servicemen. Project: 218348