Counterfeit
Fake or replica items sold as genuine. Illegal and results in permanent account bans. Facebook Marketplace's AI also flags genuine branded items — write around brand names if you're being falsely flagged.
Where you'll see this
This term is commonly used on:
ebaydepopgrailedfacebook-marketplace
Put this into practice
Shopfront handles the hard parts of crosslisting and inventory sync so you can focus on finding and selling.