Sometimes programs implement hierarchical tags, and that appeals to me the most. That way, you can navigate hierarchies of tags the same way you would navigate

Sometimes programs implement hierarchical tags, and that appeals to me the most. That way, you can navigate hierarchies of tags the same way you would navigate hierarchies of folders, but there's more than one hierarchy that can be navigated. And because you don't need to worry about encoding every piece of information into a single path, the hierarchies can be shallower and more convenient.