This read-write flag enables or disables single-bit error correction on the DS3 port's ATM Header Error Control (HEC) field, and defaults to disabled. Admins enable this setting when they want the card to automatically correct single-bit errors in cell headers rather than discarding cells outright, trading a bit of processing overhead for improved resilience on a noisy DS3 line. For example, on a DS3 circuit with a history of occasional bit errors, an admin might set this to enable to reduce the DS3-related cell-discard rate.