/h/, as was stated above. Also, unless things have changed, he is one of the few people who actually lurks /r/ (he used to be, anyhow).
IIRC, he never made it to not4chan.us
, unlike AB, who did. Of course now we're yet another not4chan beyond that, and I haven't kept up with the newest one (it got too hectic when there was not4chan, not7chan, notkochan, etc. all at once).