<?= '<?' ?>xml version="1.0" encoding="<?= $this->charset ?>" standalone="yes" ?>
<!DOCTYPE form [
  <!ELEMENT form (field)+>
  <!ELEMENT field (name, value+)>
  <!ELEMENT name (#PCDATA)>
  <!ELEMENT value (#PCDATA)>
]>
<form>
  <?php foreach ($this->fields as $field): ?>
    <field>
      <name><?= $field['name'] ?></name>
      <?php foreach ($field['values'] as $value): ?>
        <value><?= $value ?></value>
      <?php endforeach; ?>
    </field>
  <?php endforeach; ?>
</form>