Here are the explanations for all the tags [Wiki] AnKing Overhaul for Step 1 & 2 by AnKingMed
The First Aid tag was meant to be the most comprehensive tag that covers almost every card. Meanwhile BNB does not have the best tagging because the decks were not made with that resource
I believe the AnkiHub “Unified Tags” is also an example of what you are looking for. We want to phase this into the AnKing deck in the future.
This is an example of the unified tags which you can subscribe to via optional tags
This is the rationale
For the most part, tags like First Aid will stay since its the most comprehensive and we do not want to make major changes to it. However, BNB for example, has been notoriously poorly tagged and would require a better overhaul to fix the tagging discrepancies
If anyone else would like to chime in, feel free to!