I think PSA should not note them since they are too numerous and occur in many different sets. I thought the same when they recognized the 61 Fairly with a smudge of green in the baseball on the back, a defect that occurs in other 61 cards. But, having said that I do collect them
I admire the way Cliff runs down the relationships among recurring print defects by analyzing their positions on the sheets they came from. He has been extremely helpful to me in running down variants that I was unaware of due to my ad hoc approach to collecting them, that is I know one when when I see one
