power cord directionality


IF power cords do indeed have preferred directionality, and one is inadvertently flipped for a few hours, does it "harm"it?
128x128jw944ts
How can it even be used in the "wrong" direction?  Please provide more facts.
good question....I just had an umbilical made, and the Male -female ends did not correspond to the indicated directionality.....
I did not notice the directionality indication until after using it for a short while'