Format of HP S20 calibration file?

Hi all,

does anybody knows what's inside of the PhotoSmart S20 calibration file?
It looks like both original HP software and Vuescan write calibration file
in the same format, there must be description somewhere on the net, but
Google finds nothing

The problem that I'm trying to understand is so called "strobe lines"
where
even/odd lines in image differ slightly in brightness (see for example here:
http://www.photo.net/bboard/q-and-a...g?msg_id=000ukU at the very
bottom.) I have some indication that this could be related to exposure and
one of the suspects is the calibration. I'd like to look at what values are
stored
in calibration file, whether they have some interesting patters or no. Help
anyone?

Cheers,
Andy.