[RTTY] Why Send The Exchange In This Manner?

[Bob Wanderer]

My original posting was misconstrued and went off on a
tangent.  My original correction seemed to have gotten lost
in the shuffle.

The question was about the logic of sending a RST and Serial
# response in the following manner.  This is what I
received.

<my call> 599 - 121 - 121 de <his call>

The logic has nothing to do with serial # repetition.  It
has to do with why the spaces surrounding the hyphens.
Isn't that wasteful of time?  Consider how many extra FIGS
and LTRS characters are sent.  This exchange was received
from a European station.  Maybe they don't have USOS there?

73
Bob AA0CY