You must/musn't take photos here.
You musn't take photos here.
You can/mustn't park here.
You can park here.
You must/mustn't ride a bike here.
You mustn't ride a bike here.
You can/mustn't eat in the museum.
You mustn't eat in the museum.
You must/musn't use your mobile phone.
You musn't use your mobile phone.
You must/can walk your dog here.
You can walk your dog here.