Game concept
Titular Title
From the game's encyclopedia
A Titular Title is a Title that has no De Jure land on the map. Non-Titular Titles can become Titular through De Jure Drift.
Mercenary, Head of Faith and Holy Order Titles are often Titular.
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.
Titular Title is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "A Titular Title is a Title that has no De Jure land on the map." It is part of Title. 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.