Agilent Technologies ESA Series User's/Programmer's Reference page 96

Front-Panel Key Reference
File
When using a personal computer to manipulate Setup files
NOTE
(filename.set) saved to a floppy, ensure the similarly named files with
extensions like .s01, .s02, etc. are handled in a like manner. For
example, if you rename of the .set file, you must rename all the .s0x
files, as well. These files are necessary to allow complete restoration of
the originally saved Setup.
Key Access:
File, More, Format
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