One can write XSPEC commands into a file and have them executed by entering @filename or source filename at the XSPEC prompt. The save command writes out a file of XSPEC commands, which, when run, will restore XSPEC to the state it was in when the save command was issued. This command is very useful when reading a large number of data sets and/or fitting complicated models. If autosaving is operating (the default) then the equivalent of save all xautosav.xcm is run after each command, so if a disaster occurs it is possible to recover.