ds4/src/module/settings.ts

export function registerSystemSettings(): void {
    /**
     * Track the migrations version of the latest migration that has been applied
     */
    game.settings.register("ds4", "systemMigrationVersion", {
        name: "System Migration Version",
        scope: "world",
        config: false,
        type: Number,
        default: -1,
    });
}