It wouldn't be hard (albeit time consuming as all get out) to go into the tag editor, find groups of similar tags, and rename them with a common name. It's a project I'll undertake one of these days but right now, I'm up to my ample asset scanning and inputting my books so I'll continue to take the easy way out and let calibre find tags for me (it generally finds tags I never wqould have found on my own). I also take a glance to be sure tags that would be important to me are there but I generally do not have to add any. Once I finish my current project from hell, I'll have time to edit the tags calibre fetches for me so I'll have more consistancy.
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