The BPA show committee has always said show pigs can't be double tagged (but as with all committees, over time members and ideas change, so never say never

) so for showing they'd need their notch, or tatoo for light coloured breeds, and a tag
We notch all our Large Blacks and only tag (with a round button tag, in one ear) any which are being registered.
I was absolutely dreading notching, but we did them at a week old, and I have to say it wasn't nearly as bad as I was expecting

One squeel (from a complete diva of a gilt - who also squeeled at being picked up

) and no bleeding

Quick squirt of purple spray and viola, they were done.
I notch all, starting with all the boars from one litter, moving onto the gilts then continue the numbers with the boars in the next litter etc etc etc.
HTH
Karen