When I first started collecting foreign coins, I kept them all by date, mintmark and denomination. Then I switched and just collected by catalogue number and pulled out duplicates of that number. Now, in Germany for instance, I have one of each 1,2,5,10 and 50 Pfennig coin instead of a dozen or so 10 Pfennig coins with different dates and mintmarks, etc. In the end, it's my choice, but was wondering how the rest of you do it. Thanks for your comments.