TitleBG.pack
TitleBG.pack is a SARC archive which is found in Content/Pack. It contains frequently-used files that the game keeps loaded into memory in order to access them faster.
Folders
Many of the folders in TitleBG.pack are the same as those in the base Content folder, and behave in the same way. However, it also contains some new folders.
Actor
Behaves the same as Content/Actor, but also contains the additional folder Actor/AS, which contains AS files for a few (commonly-used?) cutscenes.
AnimationDrivenSpeed
Contains AnimalUnitSpeed.bin and NPCSpeed.byml.
Camera
Demo
Effect
Behaves the same as Content/Effect.
Event
Behaves the same as Content/Event, but also contains the ResidentEvent.byml file.
EventFlow
Behaves the same as .sbeventpack/EventFlow.
Map
See Content/Map for details.
Model
Behaves the same as Content/Model.
Quest
Contains QuestProduct.sbquestpack, a file which defines all of the game's quests.
Sound
Behaves the same as Content/Sound
Terrain
WorldMgr
Contains normal.bwinfo, which contains parameters for the game's environmental and weather settings.