Game concept
Budget Capacity
From the game's encyclopedia
The monthly amount of Treasury available for Treasury Budgeting. Consists of the treasury income minus any regular expenses that are not managed by budgeting, such as Vassal Development and Court Amenities.
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.
Budget Capacity is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "The monthly amount of Treasury available for Treasury Budgeting." It is part of Treasury Budgeting. Patch 1.20.1.2, from game/common/game_concepts/tgp_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/tgp_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.