[Elecraft] Question re: callsign prefixes

[VR2BrettGraham]

VE3HLS noted:

>At 2128 UTC on Sunday I heard a guy calling CQ all alone on 14038.2.  He was
>blazing along at about 35 wpm, way past my capability to keep up in a
>regular QSO, and nobody was coming back to him.  For laughs, I cranked up
>the keyer speed on my KX1 and blasted my call at him.  He immediately called
>back (nailing my call the first time) and gave me 599 - 35....zone 35, west
>Africa!  I replied with 599 - 04 and he thanked me!
>
>I spent the next 20 minutes listening to him on the KX1 and my AOR AR-7030+
>and I still can't figure out his callsign!  To me it sounded like DV4TD, but
>the only part I'm 100% sure of is "4TD".  I'm not sure about the DV part.
>I'm struggling to find a good reference for callsign prefixes.  Any help
>would be appreciated.

Don't hesitate to drop a "PSE QRS" when repeated CQs by D44TD or any other
QRQ DX in a contest are going unanswered...

A good op on the other side will drop down a cog or two to accommodate such
requests - though if one isn't getting any nibbles, going a bit slower to 
begin with
is a good idea anyway.

73, VR2BrettGraham