Cant tell but it looks like a Japanese "Kill" flag--almost like the kinds you will see on a fighter pilots aircraft--of whom shot down an enemy plane.
I think it is the "My wrinkled rectum is wide open, I am being shot at by artillery." decal.
This is a Polish Sherman correct?
Its possible that these are unofficial, pre-standardization types, temporary or even markings applied during training.
Need more info about when and where the photo was taken? What unit?
Also when I look at that barrel, I don't know if its an optical illusion or just my imagination but that barrel looks thin with perhaps a counterweight(?) at the muzzle. Plus - maybe just my imagination again - but there's something odd about that turret bustle. I could be wrong because there are variations from different Marks but I'd start with the turret.
This could be a HQ tank with extra radios etc and a dummy gun. If so that might have something to do with the markings.
Like 4thskorpion mentioned, I've also seen several photos of Polish Shermans with these markings. One thing to consider is that these markings are random and I believe applied post-war by REME workshops to identify hull repairs. I'm not entirely clear on this but I believe the locations designated repairs to significant ballistic damage. The REME used welded conical plugs/patches for ballistic piercings of the armor plate. The cross-hair was a way of measuring crack propagation/direction. Despite the Sherman's bulk it was subject to hull/chassis stresses. It's not definitive but I hope answers the question. Will put this question to some more knowledgeable folks and get back.
Well I posted a question and pictures on the G104 · Sherman M4 Medium tanks and related AFVs yahoo forum and got a better explanation to the significance of these markings. To paraphrase from forum contributor Mike he kindly explained that "it is similar to factory boresighting, but the same idea would apply in the field. A pair of tanks would probably park a specific distance apart, side by side, and on level terrain. The gunners could quickly check their periscope alignment without having to bother setting up a large target. Many of the tanks in the pictures have the M34A1 mount and boresight targets for aligning the cannons with the gun barrels. Since a lot of the tanks that the 4th had were equipped with the older M34 combination mount, keeping them aligned would be critical, especially since they probably did a lot of indirect fire missions."
Hope this information and pictures are of interest.
Here is a pdf of a factory boresighting target plan used on the M4.
Thanks Chris, for tracking this explanation down
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