Continuity
Story bible
A reference document recording a story's established characters, settings and rules so consistency survives episodes, seasons and sequels.
A story bible (in screenwriting, a show bible or pitch bible) is "a reference document used by screenwriters for information on characters, settings, and other elements" of a television, film or video-game project, kept so that established details, character development and continuity stay consistent across episodes and writing staffs. The Frasier bible, a frequently cited example, recorded family names, character preferences and a running list of Maris's food allergies so the show never contradicted itself on air.
Novelists and serial writers adopted the tool wholesale: characters, relationships, world rules, timeline and established facts in one maintained document. For a web serial it is unusually load-bearing, because chapters are published before any whole-book revision can reconcile them. See what a story bible contains.