Coin -Turn or die rotation, I believe is not a consideration until it goes beyond 15%,,,as the coin it self is considered...
There are many coins noted for "DIE ROTATION"
Usually these are known only by rotation itself...However when clashing occurs....Rotation evidence becomes increasingly evident.....
Usually on small rotations...of say, 2 degree's to say 7 degree's,,, in general we find LETTER TRANSFERS. which are
VAM points of interest....Most rotations I have seen are by nature Rotations...of per say 30, 45,90 or 180 degree's
but not ADVERTISED as letter transfers type errors...thats and interesting thought....