We wanted something simple to remember, which is why we went with icons or symbols, and I came up with the triangle-circle-X-square combination immediately afterward. I gave each symbol a meaning ...

It turns out, that “X” button (commonly pronounced “ex”) on the right side of the PlayStation Dualshock controller is actually called the “Cross” button, as reported by Eurogamer ...

As you'll no doubt remember, the order went Triangle on top, Square on left, Circle on right, and X on bottom. All normal and correct, except that it's not called the X button at all.