Craft\Workflow_SubmissionElementType::defineSortableAttributes PHP Method

    public function defineSortableAttributes()
    {
        return array('id' => Craft::t('Entry'), 'editor' => Craft::t('Editor'), 'dateCreated' => Craft::t('Date Submitted'), 'publisher' => Craft::t('Publisher'), 'dateApproved' => Craft::t('Date Approved'), 'dateRejected' => Craft::t('Date Rejected'));
    }