group.php

array(
		'name' => array(
			'notempty' => array(
				'rule' => array('notempty'),
				'allowEmpty' => false,
				'required' => true,
			),
			'isUnique' => array(
				'rule' => array('isUnique'),
				'message' => 'That group name has already been registered.',
			),
		),
)