Earlier quoted context omitted.
I don’t think you can have a public domain trademark; that doesn’t make sense with the concept. A trademark is specifically to identify the source of a product or service; if it were public domain and anyone could use it, its purpose would’ve been defeated.
I think it's a clever idea, an "open trademark". Independent certification that something fits a brand but anyone is allowed to use the brand if they pass certification. It would need a non-profit or government support though. Things like "Organic" already do that a bit, but it doesn't work too well over there.
But then it’s not public domain (which was the argument I was replying to). Public domain means everyone can do it without permission, while applying for a certification still requires a governing body which has the ultimate power.
> Things like "Organic" already do that a bit
That’s a classification, not a trademark.