[RTTY] BARTG Sprint

[Tim Shoppa]

At one point when mode reporting on cards was not so reliable, the DXCC
card checkers had some rules of thumb, like 59 indicated a phone contact
and 599 indicated a CW contact.

I think we've moved way beyond that era, the few awards I knew of that that
required QSL cards with honest RST's on them a few years ago, they no
longer require RST's.

Some of the better modern RTTY decoders can use the otherwise meaningless
but very common "599" sequence as a way of "locking" on to a RTTY signal in
the noise.

I know for sure on CW that I've heard 5NN enough that it helps my brain
synchronize and get ready for the real exchange that follows.

Tim N3QE