I have a number of locking cord ends (outlets) for extension cords that do use the holes to retain the male plug via ball detents. They require you to push a b

I have a number of locking cord ends (outlets) for extension cords that do use the holes to retain the male plug via ball detents. They require you to push a button to release the plug. https://www.homedepot.com/p/15-Amp-Stay-Plugged-Cord-Replacement-End-630-15AREPLEND/301306553 https://www.homedepot.com/p/15-Amp-Stay-Plugged-Cord-Replace... I've never seen anything else similar. I'm curious on the design of "hospital grade" plugs as that wasn't in his survey and I know that they are designed for higher retention force than commercial or residential applications.