continuum/continuum-webapp/src/main/resources/org/apache/maven/continuum/web/action/ReleasePrepareAction-releasePrepare-validation.xml

<!DOCTYPE validators PUBLIC
    "-//OpenSymphony Group//XWork Validator 1.0.2//EN"
    "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

<validators>
  <field name="scmUsername">
    <field-validator type="requiredstring">
      <message key="releasePrepareAction.scmUsername.required"/>
    </field-validator>
  </field>
  <field name="scmPassword">
    <field-validator type="requiredstring">
      <message key="releasePrepareAction.scmPassword.required"/>
    </field-validator>
  </field>
  <field name="scmTag">
    <field-validator type="requiredstring">
      <message key="releasePrepareAction.scmTag.required"/>
    </field-validator>
  </field>
  <field name="prepareGoals">
    <field-validator type="requiredstring">
      <message key="releasePrepareAction.prepareGoals.required"/>
    </field-validator>
  </field>
</validators>