YoTD was a limited run for, obviously, the Year of The Dragon.
It was available in a limited (4) number of combinations of switches and LED backlighting.
It had unique replacement FGHJ keys (with 2012 on them), and a couple of additional backlighting modes.
Plus a unique replacement Esc key (I think it was inscribed with a dragon's breath, something like that).
Each board was numbered.