Nb Perm
Diagonal corner swap: Two diagonal corners swap (plus edges); comes up 1 in 72 solves.
Algorithms
R' U L' U2 R U' L R' U L' U2 R U' L U'R' U R U' R' F' U' F R U R' F R' F' R U' Rreads as R' U · Crow (reverse) · U' · Crow · Sledgehammer (reverse) · U' R