What's also cool is that for all these, the algorithm works the same way. With a few tweaks like treating "e" and "q" as the same. It just tracks popular tag values in recent events. So we could actually track any tags with this. 

https://image.nostr.build/8a0f0363a9839c4ba29486bca0dc3a75df145389022415da1ec1d055d0b4b4f5.png
https://image.nostr.build/f8898df3654fda5affc398ed29adf5f744ed8ac95e0a812dd65a9f4c367d0497.png