Fastner Question

I can see, I confused the Locking nut with the Castleated nut.
The Locking nut version has much tighter slices, and it cannot fit a cotter pin. Im thinking those areas flex and kep it locked.
The Castleated nut has a wider opening for the cotter pin, and dont flex. Like even the older original Mopar ball joint Castleated nut has only 3 wide gaps for the pin.
Make sense?