rougail/tests/dictionaries/10valid_enum_base_no_mandatory/00-base.xml

<?xml version='1.0' encoding='UTF-8'?>
<rougail version="0.10">
  <variables>
    <family name="general" mode="expert">
      <variable name="mode_conteneur_actif" type="string" description="No change">
        <value>non</value>
      </variable>
    </family>
    <family name="enumfam" mode="expert">
      <variable name="enumvar" mandatory="False">
        <value>c</value>
      </variable>
    </family>
  </variables>
  <constraints>
    <check name="valid_enum">
      <param>a</param>
      <param>b</param>
      <param>c</param>
      <target>enumvar</target>
    </check>
  </constraints>
</rougail>