I got my visa from Belgian embassy to travel to Belguim in lorder to participate a business event out there, my visa is single entry and duriation of stay is 4 (FOUR ) day , (I can't leave my business more than one week ) . my brother is studing in France , please let me know if I am allowed to leave the Belguim toward france in my last day of trip to visit my brother and be with him for 1 day , is there any border control ? what does BNL 1 mean ? that was typed in the remarks field in my visa ..
thank you ,