Game concept
Independence Faction
The game also links it as Independence Factions, Independence.
From the game's encyclopedia
The Independence Faction seeks independence for all its members. If successful, they will go Independent from their Liege.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Independence Faction is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "The Independence Faction seeks independence for all its members." It is part of Faction. The game also links it as Independence Factions and Independence. Patch 1.20.1.2, from game/common/game_concepts/00_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/00_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.