BFF is a simple compression of FOR. (I'm trying to get away from the formation/formation set confusion. Hence, EFX represents "Encounter Sets" and BFF represents, among other things, "Battle Formations.")
Battle Formation Record
|BYTE||Battle music +1, 0 if none. (WIP functionality not implemented yet)|
|BYTE||Background animation frames -1|
|INT||Background anim speed (ticks per frame)|
|BYTE||Number of enemies, X in this set.|
The concept of an "empty record" is very unclear in FOR, since GEN stores the number of entries. Hence, BFF has no concept of "empty record elimination."