The three sacraments that leave a mark on a person’s soul are Baptism, Confirmation and Holy Orders. There is nothing scary about it.
As for the proof — when she was the VP nominee with McCain there were several FR threads about this. I wasn’t interested in copying them at that time, but wish I had now.
Marks on souls should only be done by God, not men nor an exalted denomination.
If Catholics wish to have their souls marked up by Catholic tradition, that's fine.
But let's not do it to born again Christians, such as Sarah Palin.
As far as your other comment, if you can't prove something I believe it's best if it is left unsaid.