Фишки

echo CCrmCurrency::MoneyToString(123500, 'RUB');
123 500.00 руб.

if (\Bitrix\Main\Loader::includeModule('sender')) {
   $list = array();
   foreach (\Bitrix\Sender\Subscription::getMailingList(array('IS_PUBLIC' => 'Y')) as $l) {
      $list[] = $l['ID'];
   }
   \Bitrix\Sender\Subscription::add('test@mail.ru', $list, SITE_ID);
}

use \Bitrix\Main;

Main\UserTable::getList(array(
   'filter' => array(
      'BIRTHDAY_MONTH' => date('m'),
      '>BIRTHDAY_DAY' => date('d')-3,
      '<BIRTHDAY_DAY' => date('d')+3,
   ),
   'runtime' => array(
               new Main\Entity\ExpressionField('BIRTHDAY_YEAR', 'YEAR(PERSONAL_BIRTHDAY)'),
               new Main\Entity\ExpressionField('BIRTHDAY_MONTH', 'MONTH(PERSONAL_BIRTHDAY)'),
               new Main\Entity\ExpressionField('BIRTHDAY_DAY', 'DAY(PERSONAL_BIRTHDAY)'),
               ),
))->fetchAll();

<?php
define('B_PROLOG_INCLUDED', true);
define('WIZARD_DEFAULT_SITE_ID', 's2');//site id
define('WIZARD_DEFAULT_TONLY', true);
define('PRE_LANGUAGE_ID', 'ru');//язык
define('PRE_INSTALL_CHARSET', 'utf-8');//кодировка
include_once($_SERVER['DOCUMENT_ROOT'] . '/bitrix/modules/main/install/wizard/wizard.php');

public static function OnBeforeEventAdd(&$event, &$lid, &$fields, $messageId)
{
   if ($event == 'SALE_ORDER_CANCEL') {
      /*
       * Тут ваши условия по определению, что оплата заказа стояла наличными.
       */
      $event = 'SALE_ORDER_CANCEL_CASH';
   }
}

$APPLICATION->arAdditionalChain = array();
$APPLICATION->addChainItem('Подарки к праздникам', '/gifts/');