Icons on map boxes

[PABO]

Good morning, I am a french new owner of the game. I just achieved reading the rules guide, not yet started my first mission. One think is unclear to me: what is the purpose of various icons on map boxes ( appart from "flak" one, which sounds clear to me), I mean aircraft factory, submarines harbor, railway..?
Are they only pictural indications of target on this box, or do they have a functional input on the game (which one I didn't notice in the rules book...).
Thanks for your assistance.
Regards
Pascal

 

[IronMarshal]

The railroad, airplane, submarine symbols represent the type of target in that box. The gun icon indicates a flak check must be made whenever a squadron enters the box during the solo game. In the 2 player game the German player uses his flak counters to attempt flak attacks.

 

[PABO]

Good afternoon, thanks for your answer. So, as far as I understand, any other icon than "flan gun" is just an "illustration" (of the target type) but without any active participation in the game.