Originally Posted by
Murty
AFTN Message Format
The Message Text ends with the End-of-Message Signal, which is the four characters NNNN. The Ending itself comprises twelve letter shift signals which represent also a Message-Separation Signal..
twelve "letter shift signals"? We're talking Baudot teletype code (5-level, ITA2) here, which has been obsolete for about 60 years.If the system had upgraded to 8-bit codes you could use the specalized message separation characters SOH, STX/ETX, ETB/EOT, not to mention FS/GS/RS/US. I suppose no one wanted to take the hit for suggesting such a radical change.