Epson 10020 - Manual (Page 75)

As the number of files in your WORDPROC and SPDSHEET
directories grows, you can create additional directories
subordinate to those two-like this, for example:
This structure would let you segregate your business word
processing files from your personal word processing files, and
your sales spreadsheets from spreadsheet files used for financial
projections.
Your directory structure may be as simple as this example or it
could be much more complex. Organize your disk(s) to suit
your own needs, and you can always delete old directories and
create new ones as your needs change.
Here are some additional points to note about directories:
In the root directory, the total number of files and
subdirectories must not exceed 512 on the hard disk and
112 on a 360KB diskette.
All directories other than the root directory can have any
number of files and subdirectories.
Subdirectories are named the same way files are. The name
can include as many as eight characters, and you can add
an extension of up to three characters.
The root directory does not have a name. It is identified by
the backslash character: \.
Diskettes have root directories, just as hard disks do, and
you can create subdirectories on diskettes the same as on
hard disks.
3-16 Using MS-DOS With Your Computer