[Quack me up!]

Is there an area here on the forum or in printed form where the known barrel flat markings are described and explained if possible?
I know people will post their own inquiry about a certain barrel mark here on the forum but is there a place where I can find these explained and all together instead of having to search individual threads for explanations?
I'm interested in any such markings even if there is not a known explanation for a certain mark or stamp.
Thank you.