Minecraft wiki entry for World_border, associated text: level.dat
 Data
 BorderCenterX: center of the world border (X-axis)
 BorderCenterZ: center of the world border (Z-axis)
 BorderDamagePerBlock: damage taken per block moved outside the world border
 BorderSafeZone: distance in blocks of the buffer zone where damage is not taken when outside the world border
 BorderSize: world border diameter
 BorderSizeLerpTarget:[more information needed]
 BorderSizeLerpTime:[more information needed]
 BorderWarningBlocks: maximum distance away from the border where the border warning overlay appears on the player
 BorderWarningTime: time in seconds[verify] until the border warning overlay appears