Open selections

• Allow the user to specify a value not in the list

• selection="open" attribute

<select ref="pz:toppings" selection="open">
  <label>Flavors</label>
  <choices>
    <item>
      <label>Pepperoni</label>
      <value>pprn</value>
    </item>
    <item>
      <label>Ham</label>
      <value>ham</value>
    </item>
    <item>
      <label>Pineapple</label>
      <value>pnnp</value>
    </item>
    <item>
      <label>Anchovies</label>
      <value>anch</value>
    </item>
    <item>
      <label>Garlic</label>
      <value>garl</value>
    </item>
    <item>
      <label>Sausage</label>
      <value>ssge</value>
    </item>
  </choices>
</select>