Game concept
Vassal Contract
The game also links it as Vassal Contracts.
From the game's encyclopedia
Vassal Contracts dictate the Obligations between a Vassal and their Liege.
Vassals of the Feudal, Clan, Administrative and Nomadic Government Forms have access to different Obligations, negotiated individually for each Vassal.
All Vassals pay a percentage of their total Taxes and Levies to their Liege, based on their Obligations. These Contributions can in turn be modified by 'fine print' options such as Fortification Rights Granted.
Some Special Contracts are limited to certain Ranks:
• March Contract and Scutage Contract: Duke and above
• Palatinate Contract: Count and above
• Castellan Contract: Count only
Note, Governor Obligations are also known as Province Administrations.
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.
Vassal Contract is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "Vassal Contracts dictate the Obligations between a Vassal and their Liege." The game also links it as Vassal Contracts. 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.