I have lived in Delaware for 50 years and I can't recall seeing anyone open carry. Unless they are like me. I have a DECCW and carry all the time. Some times around home I O/C, not as a rule. I heard a story once about someone carrying in the Georgetown Walmart. A customer complained to the manager and the manager called the city police. The manager told the policeman on the phone, that a customer was in the store open carrying a pistol. The policeman asked what the person was doing. Well, he was shopping for groceries she said. Is he bothering or threatening any one, or is he taking the gun out of the holster, asked the police? No, he shopping she said. Well then he is not breaking any law, the policeman said. We can't do anything. The manager said, well can't you come over and make him cover the gun up? No said the policeman, if we make him cover it up, and he doesn't have a CCP we would be asking him to break the law. Since Walmart has no national corporate or posted policy against carrying a gun in the store there is nothing you can do. The manager huffed and grumbled and slammed the phone down.
I got this story from a Licensed fire arms instructor that is also a police officer.