When is the transmission of codes or ciphers allowed to hide the meaning of a message transmitted by an amateur station?

The transmission of codes or ciphers to conceal the meaning of a message sent from an amateur station is permissible specifically when transmitting control commands to space stations or radio control craft. This rule exists because the command and control communications for these types of operations often require secure methods to prevent unauthorized access or interference.

For amateur radio operators, adhering to regulations is crucial, and the use of codes or ciphers is generally prohibited in most contexts to ensure that transmissions are open and accessible to all other operators. However, the unique nature and operational needs of controlling space stations or radio-controlled craft necessitate an exception, allowing for the use of coded messages in these specific circumstances.

The other scenarios outlined in the incorrect options do not qualify for this exception, as they do not pertain to the specialized requirements of command and control operations. This regulatory framework aims to maintain transparency and facilitate amateur radio's primary mission of open communication among operators.