IBM 3270 Manual page 40

Your diskette is now formatted and the
portions of DOS that you will need have been
copied onto it.
9. Make up a name for the volume label on your
system diskette. This name can be from 1 to
11 letters long. For example:
systerndisk
This label will help you identify your system
diskette when you ask for information about
it. Make a note of this name for the diskette
label.
10. Type your label after the question mark.
Volume label (11 characters, ENTER for none)? systemdisk
Make sure that you did not type a blank at
the beginning of the name.
11. Press the Enter key, and wait for these
messages to appear on your screen:
nnnnnn bytes total disk space
nnnnnn bytes used by the system
nnnnnn bytes available on disk
Format another (YIN)?
The values shown by nnnnnn are replaced by
decimal numbers.
Chapter 1. Setting Up the 3270 PC Control Program 1-31