I realize this is an older thread, but it's so easy I couldn't pass it up. The illustrations below should answer your questions and hopefully assist you in the future. The numbers other than those connected to the <(I)> are mold/tracking, etc., and of no real importance. The shard you posted appears to be 1938. An 8 (no dot) = 1938 ... An 8. (with dot) = 1948 And if you would like to "Read all about it" this link has "The rest of the story."