OK, I confess to be a "lumper" and not a "splitter" - maybe comes from being a biologist, where a few of us classical types don't care a lot for pigeonholing as there was and is a tendency to get lost in the forest for the trees. So, my vote (for whatever it counts) is to have an entirely separate catalogue for wide and narrow, and data variants (save the overdates), and the like. To present a countering view, I think, to what has been proposed - I think an overdate is far more obvious to the observer than a date spacing die variant. And quite frankly, though admittedly a matter of personal perspective, I think listings in a general catalogue ought to be obvious as to type to even a beginner or slightly advanced collector/cataloguer.