When is it permissible to transmit messages encoded to obscure their meaning?
Only when using a remote station during a contest
Only when transmitting certain approved digital codes
Only when transmitting control commands to space stations or model craft✓Bonne réponse
Never
Explication
Encoding to hide meaning is prohibited in general, with two narrow carve-outs: telecommand of a space station and control signals to model craft. Approved digital codes such as RTTY or FT8 are published protocols, not attempts to obscure meaning, so they are not an exception to the rule.