Drupal 7 custom view mode

drupal7_view_mode.php

<?php

/**
 * Implements hook_entity_info_alter().
 *
 * Add view modes .
 */
function MYMODULE_entity_info_alter(&$entity_info) {
  // Add 'listing' view mode
  $entity_info['node']['view modes']['listing'] = array(
    'label' => t("Listing"),
    'custom settings' => FALSE, // Do not enable this view mode for all content types by default
  );
}