Hi, Gentoo!

I've just got a sparkling new installation of Gentoo on my new PC. It
only took me ~5 hours, mainly because I'd already configured the kernel
in a trial run. :-)

However, I'm now trying to get X up and running. "The X Server
Configuration HOWTO", section 3. "Configuring Xorg" says:

"Hal comes with many premade device rules, also called policies.
These policy files are available in /usr/....../policy. Just find a
few that suit your needs most closely and copy them to /etc/...."

"For example, to get a basic working keyboard/mouse combination, you
could copy the following files...
/usr/.........../10-input-policy.fdi
/usr/.........../10-x11-input.fdi"

. Am I the only person that finds this semantic gibberish? Is there
any explanation somewhere of what a "policy" aka "device rule" is? What
is the semantic significance of a "device rule"? What does it mean, to
"rule a device", or what sort of restrictions are being placed on this
device?

Given that one might desire a "basic working keyboard/mouse
combination", what is the chain of reasoning that ends up selecting the
file called "10-input-policy.fdi" from all the other ones?

This file is an inpenetrable stanza of uncommented XML. Are its verbs
documented somewhere? What do "<match ...>" and "<append ....>" mean,
for example?

Can this new-style fragmented XML configuration do anything that a good
old-fashioned, human-readable and compact xorg.conf can't? If so, what?
What am I missing here?

Please, somebody, tell me all this HAL stuff is straightforwardly
explained in an easily accessible Gentoo document, so that I can hang my
head in shame and apologise for the noise! ;-)

--
Alan Mackenzie (Nuremberg, Germany).