Pleiades is correct, I believe. Minimum clearance in roller rocker engines.

I'd just like to add that, in my experience, aluminium engines with roller rockers tend to sound terrible if valve clearances are set even a little bit wide.

A 610E Husky I owned had .002" clearances all round (from memory). Only a couple of thou more and it sounded awful. I also had the enduro 610 and (later) a 570 with 004" and 006" settings, and they rattled something terrible. Bloody great bikes, though. Especially the 570.

This probably why my Tenere is sounding better now than when I set the clearances mid-range 16,000km ago. Scared...