prolog.php

См. документацию.

<?php
IncludeModuleLangFile(__FILE__);
define('ADMIN_MODULE_NAME', 'subscribe');
define('ADMIN_MODULE_ICON', '<a href="/bitrix/admin/posting_admin.php?lang=' . LANGUAGE_ID . '"><img src="/bitrix/images/subscribe/subscribe.gif" width="48" height="48" border="0" alt="' . GetMessage('subscr_prolog_title') . '" title="' . GetMessage('subscr_prolog_title') . '"></a>');