[necovek]

Sarcasm is, by definition, use of irony to be a bit meaner than just make fun of something. It's still irony, and I am not even sure it qualifies for the sarcastic qualities on top.

I find that sarcasm or irony are pretty frequent on HN, or maybe it's just me who thinks it is so. ;-)

[IndySun]

I think your definition is acceptable, in this forum context.

And yes, I see it here too, and try to reward it, though, alas, you and I are few.