Minecraft wiki entry for Schematic_file_format, associated text: The .schematic file format was created by the community to store sections of a Minecraft world for use with third-party programs (including MCEdit, Minecraft Note Block Studio, Redstone Simulator, WorldEdit, and Schematica). Schematics are in NBT format and are loosely based on the Indev level format. Indices for the Blocks and Data arrays are ordered YZX - that is, the X coordinate varies the fastest. This is similar to block ordering for Classic, Indev, and Anvil levels. This format cannot store or distinguish air blocks that should overwrite existing blocks from those that shouldn't.