[mac01021]

But presumably there is more than one brand of Blue d'Avergne? I'm not suggesting one should be able to steal the trademarks of any of those brands.

And if someone from a different place makes a product that is compositionally identical then probably their ability to market it will depend on the customer's recognition that it is exactly the same thing.

[jinglebells]

You're confusing brand/trademark with origin labelling. A farmers market will inevitably have multiple cheeses created by different producers, all of which may be labelled "Blue d'Avergne".

Yeah, brands do happen, I bought a cheese labelled "Blue style cheese" the other day because it was cheaper and may have been made in Poland to the same process.

[barrkel]

Blue d'Avergne is the brand. There may be more than one producer that follows the established rules for the brand.