From the 1st January 2011 the rules changed and notching became the BPA requirement for OSB pedigree pigs. Any pig born prior to this date may have been tattooed or notched by the breeder. An ear tag is also required to match up with the ear notching and will show the Breeders HDL, the individual ID number of the Pig and on the underside, the Breeders Herd Number.
You do not need to tattoo and ear notch. The BPA does have provision for double tagged pigs but this is by agreement with them. Double tagged pigs cannot be shown at BPA Shows in OSB Breed classes. Hope that helps.