Mark Layman from Colorado sent me a photo of his invasion arm flag that looks the same as my type 3, except that it has the letters CL printed in black on the inside. I remember seeing a similar arm flag somewhere, but with a different text. But I can’t find the photo anywhere… I can only guess what CL means. Combat Leader comes to mind, but obviously one wouldn’t want to wear that plainly visible on a white armband. I’m thinking rather something for Civilians, eg Civilian Laborer. The U.S. had patches for non-combatants, but maybe the brassard was an improvised means of clearly pointing out civilians authorized to perform some task helping the army.
If anyone knows or owns a similar type of arm flag printed on the inside, please send my a photo.