Wii Auto Erase Disc
The Wii Auto Erase Disc is a disc that authorized repair centers used to quickly format a Wii NAND to factory defaults. This was used in order to protect the customer's privacy.
In early 2022, a person named b3l0kk that works at a console repair center posted a picture of the Wii Auto Erase Disc to a site called TheGamesDB. When contacted about the disc, they willingly preserved it to Redump, a disc preservation project. They have 2 copies that they bought via eBay.
A Nintendo employee responded via email that they haven't received requests to obtain a Wii Auto Erase Disc since around 2012, and they recycled the unsold discs in around 2017. They also confirmed the Wii U doesn't have an auto erase disc.