Game concept
Organized
From the game's encyclopedia
An Organized Faith has a religious hierarchy. Worship and practices are more organized and scriptures are formalized.
Unreformed Pagan Faiths can become Organized by reforming, while other Faiths are always considered Organized.
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.
Organized is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "An Organized Faith has a religious hierarchy." 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.