1. Ebay encourages people to list items in multiple catagories as this increases the amount of money that they make. A new catagory will not necessarily stop people from either listing in more than one catagory or just plain ignoring the new catagory.

2. What you might want to do as an alternative is suggest a disclaimer be added to the posting screen for people who list items for sale similiar to what they have for coins, banknotes, etc. I do not have the exact words, but can get them for you if you wish. Basicailly, on the preview screen, at the bottom, right above the button that you push to post an auction lot is a highlighted box stating that the stuff that you are selling is what you clain it to be. I think that this might be a better route to go.

John