Индекс сокращенного набора номера - in Russian, it means a short number (like 3 digits) that a company can buy from a mobile phone operator, so that the company's customers can dial for some SMS or media service (e.g. receive a weather forecast, or download a ringtone, etc., by dialing a very short number).
In Russian, "индекс сокращенного набора номера" (ИСНН) is an established term, well-known in the industry. What is its English equivalent?