    <dd>Refer to the most recent command starting with <var>string</var>.

     <br><dt><code>!?</code><var>string</var><code>[?]</code>
     <dd>Refer to the most recent command containing <var>string</var>.  The trailing
<code>?</code> may be omitted if the <var>string</var> is followed immediately by
a newline.

     <br><dt><code>^</code><var>string1</var><code>^</code><var>string2</var><code>^</code>
     <dd>Quick Substitution.  Repeat the last command, replacing <var>string1</var>
with <var>string2</