Today I learned there are IEC cords with lock-in mechanisms. The cord came with a machine where it definitely does not lock in. I can only imagine the OEM selected it because it matched the colour scheme on the box.

I used the cord on a random appliance and it would not come out again until I found the release on the cord and pressed it. So today, I also learned that random appliance IEC sockets may support lock-in. The hidden functionality in standards is an amazing thing.

I have no idea why I don't know about IEC lock-in. I googled for an image and I see what looks like more than one type.