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.
... for much less money.
Quackery today
The most common products that are being sold, and are considered ineffective by experts are herbal medicines. These are ...