The Wipers Times

[ColinB]

is it not similar to WW2 where officers had white stripes on the back of their helmets to delineate them from the rest of the bods, without making them a target?

Weren't the stripes on the back of helmets gas detector paint so you could see if gas was present by looking at the person in in front of you? This was supplemented by the use of brassards.

[Wensleydale]

My badge theory? Moving around at night was a hazardous occupation during WW1 - especially when you had to follow the chap in front along the myriad of communications and supply trenches. Even in the rear of the trenches, just one slip off the duckboard could prove fatal. However, when patrolling no-mans' land at night, one had to follow the correct chap through the gaps in the wire while maintaining complete silence.

I suspect that the badges greatly helped unit cohesion in this game of "follow-my-leader".