If you are running the DCU on an ASCII terminal or an X-terminal, the named keys may not work if they have been remapped. In these cases, you can use a sequence of alternate keystrokes that, when typed, are equivalent to pressing that named key.
For example, you can access online help while using the DCU by pressing <F1>. If the function keys on your terminal do not work, you can press <Ctrl>+<F>+<1>. This sequence is typed by holding down <Ctrl> while pressing <F>, then pressing <1>. The sequence of alternate keystrokes for <F10> is <Ctrl>+<F>+<0>.