The Yellow Card Man

For Christmas, our son gave me Stephen King’s recent novel, 11/22/63.  (He might have chosen a more mellifluous and less mouth-filling a title, I must say;  mais passons.)  A quite intriguing minor character is the “Yellow-Card Man”.  What he is up to, I cannot yet say;  but consider this predecessor, from a century before:

Der Leiermann

And this, where he appears with a different symbol, other than the yellow card:

     The Umbrella man in Dealey Plaza