How to adapt the name of a custom Drush command?
You would have to change a couple of things:

/**
 * Implements hook_drush_command().
 */
function drush_content_types_drush_command() {
  $items['mijn-contenttypes-lijst'] = array(
    'description' =&gt; dt("Show a list of available content types."),
    'aliases' =&gt; array('mcl'),
  );
  return $items;
}


The array key under $items and the "aliases" value under that need changed. The array key is used to identify the callback to invoke when using the drush command or alias. The callback, for whatever reason, doesn't start with the command file prefix but rather starts with "drush" and then the command file prefix and then the array key listed above replacing the dashes with underscores. So the second (callback) function would look like...

/**
 * Callback for the content-type-list command.
 */
function drush_drush_content_types_mijn_contenttypes_lijst() {
  $content_types = array_keys(node_type_get_types());
  sort($content_types);

  drush_print(dt("Machine name"));
  drush_print(implode("\r\n", $content_types));
}


Making those changes should give you what you want. More information about creating your own drush commands can be found here: Command Authoring