<header>Runlevels</header> The field may contain multiple characters for different runlevels. For example, <tt>123</tt> specifies that the process should be started in runlevels 1, 2, and 3.<p> When the system runlevel is changed, any running processes that are not specified for the new runlevel are killed, first with <tt>SIGTERM</tt>, then with <tt>SIGKILL</tt>.<p> <hr>