dChan: use this rule for edge orientation:
If an edge can be put at its destination spot, oriented correctly, without using L, L', R, R' it is oriented correctly, otherwise it is not.
The number of mis-oriented edges cannot be odd.
Consider this example (I am assuming white at the bottom, red at the front):
D U L B2 R' D2 U R D2 U' F2 D U2 B F2 D2 R F L D R2 U F U2 B2 R2 B U' B' F'
Green-Yellow: mis-oriented
Blue-White: mis-oriented
Green-Red: U2 F, so correctly oriented
Blue-Yellow: mis-oriented
White-Green: mis-oriented
Orange-Blue: F2 L2, so correctly oriented
Blue-Red: mis-oriented
Red-White: L2 F', so correctly oriented
Orange-Green: mis-oriented
Red-Yellow: mis-oriented
Orange-White: mis-oriented
Yellow-Orange: L2 U, so correctly oriented
8 mis-oriented