[Molon Labbie]

You hit it right on the head, it is an identifier and apparently it is a contaminant during the recycling process.

[TigersEye]

So I got it on both counts? I do get lucky sometimes. I was wondering about it being an identifier because sometime in the future it might be legitimately scrapped. I suppose the scrapper could then produce some document showing a legitimate source though such as a contract to demolish an old building.