Hamming?
Dx'ing – that's something a long way from contesting. You find someone in
deepest, darkest walla-wa-frump, and you talk to them, learn about what
they do, why they are there, what it's like, and etc. You send them a nice
QSL card, and you both remember the event.
Of course, that's the way I DX… certainly there are those who make it a
contest – I have no use for them at all.
And I'm not at all sure that being a dx'er ever requires the "certificate".
As soon as it's a contest, it's no fun to me.
Not that I dislike contests in general, but HAM radio offers so much more,
a contest only sullies the "good stuff".
Oh well.
–Ben