To display context help for an available button in the toolbar,
right-click that button.
If a button is unavailable, select
one or more objects relevant to the operation of the button. For example,
the Describe button appears dimmed until
you select a type object that can be described.
To display button help for an available command, click the
menu, use the arrow keys to navigate to the subcommand of interest, and press
F1.