True. I think he's talking about this (image below). Basically, a 3rd party company took standard bullion coins (in BU condition) from 16 different countries and stamped its own “W16” Privy mark on top of them and then declared them to be a special limited edition set. Call it “creative marketing”? :-)
However in doing so, this just results in PMD (Post Mint Damage). I sure wouldn't want a 3rd party stamping anything on my ASE.
Thanks. So to answer the OP's question…Because they are out of the scope on Numista, for good reason. You add them to your collection by adding the Official coin and making a private or public comment that they are from the W16 collection.