One possible use of this bug is a way to organize characters in multiple ways, but still only reference a single character. For example, if you are running the entire D&D Essentials Kit, you'll get monsters of various CR levels from each of the 4 modules. So if you wanted to be able to sort your monsters alphabetically, by CR level, and also by which module you got them from, the bug that allowed linked duplication would let you create a folder that has monsters listed alphabetically, another folder listing by CR level, and another folder that separates them by module. Unfortunately it is indeed a bug, and not a feature, so there's always a chance that even if you can figure out how to do it on purpose, that some future software version will eliminate it as a possibility. If this is what you are trying to do, then I'd suggest picking a single method as your primary sort, and a second as your secondary sort. Personally I use CR as my only sorting method for generic NPCs, and I have a separate folder for named NPCs. Anything else I can simply use the search feature to find a specific monster quickly.