Someone has managed to reverse-engineer HDCD encoding:
http://www.srcf.ucam.org/~cjk32/hdcd

So now it's easy to decode an HDCD to a 24-bit file and see whether
each track has 'Peak Extend' and/or 'Low Level Range Extend'.
Looking at a few (King Crimson) CDs last night, only three had 'Peak Extend'
of which none actually needed it as they wouldn't have clipped anyway.

Any volunteers to correct the Wikipedia entry,
http://en.wikipedia.org/wiki/HDCD ?

--
Eiron.