New region

I read the Drupal's manual to introduce a new region in the subjects. In Deco however I do not find deco_regions.
There it is? or how I can do? Thanks and excused my English.

function mytheme_regions() {
  return array(
    'right' => t('right sidebar'),
    'content' => t('content'),
    'header' => t('header'),
    'footer' => t('footer'),
    'floater' => t('floater'),
    'inline1' => t('inline 1')
  );
}