Plus pattern

Each face keeps a plus sign in its own colour, while its four corners swap to the opposite colour.

U F B' L2 U2 L2 F' B U2 L2 U

U F B' L2 U2 L2 F' B U2 L2 U

Plus pattern

To undo it, play it backwards with each move reversed: U' L2 U2 B' F L2 U2 L2 B F' U'.

U' L2 U2 B' F L2 U2 L2 B F' U'

Undo the plus pattern

Common mistakes

Mixing up F and B'. Both turn the same way when you look from the front. That's why one is primed.