Electric plug and socket types around the world

I looked at the type A&B page and it said this:

>Type A and B plugs have two flat prongs with (often, but not always) a hole near the tip. These holes aren’t there without a reason.

I'm given to understand that isn't true. That "Technology Connections" YouTube guy has a video on this and it conclusively debunks this assertion.

If I find what's essentially an urban myth in my first look at details, I'm inclined to ignore everything else it says.