maction-01

You should see word PASS once you place mouse pointer over box below

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <maction actiontype="tooltip">
    <mrow>
      <menclose notation="box">
        <mtext>Place mouse pointer over this box</mtext>
      </menclose>
    </mrow>
    <mtext>PASS</mtext>
  </maction>
</math>

Author: George Chavchanidze, Opera Software ASA