The US plugs that have a sideways T are the lower amperage compatible style, but everything over 20A has a plug that is circular in arrangement. You can put a 10A in the one with a sideways T, but not the converse, because the hot leg is rotated 90°.
To be fair I've never seen that plug in the wild, but I don't go out much.
To be fair I've never seen that plug in the wild, but I don't go out much.