islandora/islandora_mods/islandora_mods.install

<?php

/**
 * @file
 * Install hooks for this module.
 */

/**
 * Implements hook_install().
 *
 * Creates shared fields for content types using MODS metadata.
 */
function islandora_mods_install() {
  $t = get_t();

  $mods_field = array(
    'field_name' => ISLANDORA_MODS_FIELD,
    'type' => 'xml_field_xml',
  );
  field_create_field($mods_field);
  drupal_set_message($t("Created field @field",
                     array("@field" => ISLANDORA_MODS_FIELD)));
}