     Most Multics "commands" and "control arguments" have short names to
facilitate typing.  These short names are listed in the command descriptions,
which you can obtain with the help command or by looking them up in the
printed manuals.  The short names can be used anytime in place of the full
names.  Let's take the list command as an example.  Its short name is ls,
and most of its control arguments also have short names.  In the "command line"
below, can you tell what the control argument -dir stands for?

ls -dir

This is the list command invoked to list directories. 
