A step by Step Solution of Rubik's "Magic Cube"
6. Put U edges in place. (contents)
6.c. In one case out of six, there will be no U edge pieces correctly in place and two adjacent pairs of edges want to be exchanged. Turn the cube so you want to exchange UF with UR and UL with UB, as shown. (hide)
Apply R2D2B2D·L2F2L2F2L2F2·D'B2D2R2.