Tire plugs

I appreciate all the responses. The reason I asked the question is because a couple of days ago, while camping, I noticed a screw in my right rear 5er tire. I took it off and went to the only tire repair shop within a 45 minute drive. (which would have been down the mountain and back up) They only did plugs, as they did not have the equipment to remove a tire from its rim. The guy that plugged it said the hole went straight through and was clean and easy to plug. I wasn't sure what that meant till reading these posts. Anyway, when we got home, I had that tire taken off, the spare replaced with a new one,(spare was 5 years old or so) and now the plugged tire is being used as the spare. Before ok'ing the plug, I called my tire dealer, who has been in local business 50+ years, and is well respected locally, who said the plug would be fine. It was my choice to trade the tire for a spare. Anyway, thanks for all your very helpful responses. If it ever happens again, I'll have more information to base my decision on. You've all been very helpful.