There is no reason at present to create book Because:
1. When player is combat or flag it shouldn't have output a message? "You Cannot use the buffer in combat!"
2. When player is out from town cant open it.
I finally removed it.
The way i found is simple:
1. Go gameserver\data\html\mods\buffer
There is the old buffer , put your code in the files of the old.
and put the bypass of the old npc buffer