This object specifies the backward signal requesting the far end simply resend the very last digit it transmitted, without rolling back further. This is the simplest and most immediate digit-error recovery signal in the family, used when the gateway detects a problem with only the most recently received digit and wants the cheapest possible correction rather than invoking the deeper rollback signals. If the last digit received reads as an invalid tone due to a brief line glitch, the gateway would send this signal to get just that one digit repeated before continuing.