Checkerboard uniforms?

I was rewatching the "Victory at Sea" series several years ago, and a peculiar uniform addition caught my attention. In the episode about the return to the Philippines, there's footage of a 37mm gun crew firing on the Japanese in Manila. The backs of gun crew's jackets are divided, shoulder to belt, into two black and two white checks - very large and regular, and hard to mistake for something else.

At first I though it was some sort of training footage mixed in, but the same backgraound seemed to be the same area shown in the adjacent combat footage.

Last week I was rereading Morison's volume on the Gilberts and Marianas. Morison loved to add in details of uniforms and colors from time to time, and he mentioned the troops going ashore with black-and-white checkerboard identification markings on their jackets. (I promptly stuffed a bookmark into the page, but it has since fallen out!)

So - what have I been missing? I've seen only these two references to to jacket markings - were they often used? Are there photos in books that I just haven't seen yet? I assume that the checks were lightly sewed in place for quick removal - or were they integral to the jackets?

I'd love to know more, especially since I've never seen figures with these markings on the contest table and it might be fun to stir up some discussion...

Cheers,

Dana