In telecommunication, an error-detecting system is a system employing an error-detecting code[?] and so arranged that any signal detected as being in error is either deleted from the data delivered to the data sink, in some cases with an indication that such deletion has taken place, or delivered to the data sink together with an indication that the signal is in error.
... usually consist of a car battery, hooked up to two metal plates, in a medical-looking box. They receive a lot of money, and cite a lot of people cured. These people ...