Ok, if they are different, then why does it matter that I have the same tag in a different notebook? In any case, the tag should be only unique per notebook, not across the entire evernote database.
For example, when I tag a specific notebook, it should only pull from the tags available for that particular notebook, and should not care about the tags in my other notebooks. If someone else shared a notebook with me, when I tag in that notebook, it should only look up the tags available for that notebook, regardless if I have a million other tags in my own notebooks, as those don't matter and should be ignored.
Make sense?