Useful when multiple subcircuits should be saved to be reused as a library. When first argument is dir, each subcircuit is saved in a separate, numbered file. If the first argument is file and the target file format has library support, all subcircuits are saved in the same file, as a library.

If a single subcircuit from buffer needs to be saved to be a footprint, use the SaveTo action with first argument set to PasteBuffer.