help determine the flag

[YURYI]

Who can identify this flag...

[GregSingh]

Funny photo.
I think flag is behind the bike and it's a waterway traffic sign. Meaning: traffic restrictions as outlined below - can't see what's there, could be time of the day or similar.
E.g. if it's a lake - can't use a boat from- to-

[YURYI]

[von thoma]

According German tactical symbols, a square identifies the German infantry.
On the fender of the bike, has the symbol of Infantry Gun Company ( Motorized ).

[YURYI]

what does this symbol

[YURYI]

According German tactical symbols, a square identifies the German infantry.
On the fender of the bike, has the symbol of Infantry Gun Company ( Motorized ).

SIGN OF COLOUR

[von thoma]

The circle it's for motorcycle units.

[GregSingh]

Thanks guys! Nice photos YURYI.