If you hover your mouse over the boards, you get the descriptions, which clarify.
Pulled off a "human" board: Games encompassed in a single thread that involve sex with consensual bondage and feature characters who are human in form or very near (e.g., elves) and either male or female gender
Pulled off an "exotic" board: Games of less than 1000 posts on multiple threads involving sex consensual with bondage and include hermaphrodites (futa) and/or nonhumans (such as furries, beasts, tentacle monsters, etc.)