What workaround are you referring to? With me and my wife it seems to work. I add a note in *her* notebook, and add tags that are available in *that* notebook. I can't use her tags in my notebook, or rather, I just create them new, for my notebooks. I have discovered that it appears to be a bug in the OSX version as I can do what you stated, use tags that the owner of the notebook has previously used, in the web version but the OSX app gives me an error and refuses to let any guest assign tags, regardless if they have been used by the owner already.