Minecraft wiki entry for clone, associated text: clone <begin: x y z> <end: x y z> <destination: x y z> [maskMode: MaskMode] [cloneMode: CloneMode]
Clones all blocks or only non-air blocks.
clone <begin: x y z> <end: x y z> <destination: x y z> filtered <cloneMode: CloneMode> <tileName: Block> <tileData: int>
clone <begin: x y z> <end: x y z> <destination: x y z> filtered <cloneMode: CloneMode> <tileName: Block> <blockStates: block states>
Clones only blocks with the block id specified by <filter>.