Rabbit, it may be a Guide written by a seller but it is well researched and is a very good summary of information available on the internet in general.

As for the 9/10 carat information.....9ct is the standard in Australia but 10k is more usual in the USA.  If we are talking ebay staff here I would think they are only going to recognise 10k and decide the 9ct is not within their rules, despite the rest of the world being OK with 9ct.

What exactly is the problem?  Are you trying to list something as Vermeil Gold or has someone else got something listed that you are suspicious of?

A lot of vintage/antique jewelley is listed as Vermeil Gold Wash when it should just be Gold Wash...it is a very thin layer of gold that can wear off with a few good polishes.