New or existing tags we add to annotations in the beta pdf editor are visible in the normal tags window, but they don't select the item or its children.
Yes, annotation tags are currently limited to filtering annotations in the PDF reader sidebar, but they'll be available for other parts of Zotero in future versions.
Tags that are only on PDF annotations shouldn't show up in the library view yet. That's a bug, and we'll fix that.
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Tags that are only on PDF annotations shouldn't show up in the library view yet. That's a bug, and we'll fix that.