Marc,

Interesting question. The ChipGuide does its best to only provide factual information. We generally provide information that has been previously authenticated by a known and respected resource. The Gaming Table, The Chip Rack, Dick Staefler's California Cardroom Guide and many other collector guides and references are used. When we have reason to believe but are not quite sure, then we indicate that by using the phrase "Attributed to ... ".

There are chips they we know of, but are not known in any collection. We mainly learn of these types of chips from manufacturer's records. If we have reason to believe that a chip existed, then we want it noted on the ChipGuide, whether or not someone has one in their collection.