[RTTY] I had a reply in the contest from a fellow using cw for rtty

[Tom Osborne]

Yes, you definately didn't want to start printing CW with the mark signal in 
the middle of a picture being received :-)  73
Tom W7WHY




Besides IDing on RTTY, you were required (on HF) to ID with
telegraphy.  You could use CW or FSK telegraphy.  The simplest
way to comply was to generate CW by keying your mark signal, but
that would usually produce garbage print on the receiving end.
To avoid that, lots of us used narrow shift (20 Hz or so) FSK for
IDing.

73,  Arliss  W7XU