Small Scale Military Headquarters

I finally took my FOV 1/72 M3 Lee out of the package and noticed that in the center of the small pile of gear that comes as an accessory there is a round hole. Anyone have an idea what this is for? None of my other FOV accessories will fit this.

I could put a custom flag in here but I would think there is an explanation for this.

I don't think its a hole for some sort of peg, but rather simply a detail on that stowage piece. Perhaps its something like a bucket or empty can.