Biomes have these lovely tags associated with them:

https://pastebin.com/raw/0NH383ps

Several mods can/do hook into these tags for determining where things generate. Quark, Doomlike Dungeons, COFH world, come to mind off the top of the head.

Currently, to my knowledge, there is no publicly available way to see the tags for an end-user if a mod is using them in their biomes, and it struck me that that is the perfect sort of feature for Tellme.

If you have the time, ambition, and desire, of course. Thank you for your time and consideration.