Minecraft wiki entry for Item_format, associated text:  tag: Parent tag.
 map_is_init: (May not exist) Unknown.
 map_uuid: The uuid of the map used in this item.
 map_name_index: The index of the map's name.
 map_display_players: (May not exist) Whether the map displays player markers.
 map_scale: (May not exist) Unknown.
 map_is_scaling: (May not exist) Unknown.