Two days ago I started touching the FAQ chapter in the pkgsrc's Guide and I literally opened a can of worms. The thing is that I started to rewrite the question about configuration files placement (because most of the answer was just internal details of pkgsrc) and ended up writing a whole new chapter about the pkginstall framework. Hope it's an interesting read for you ;)
Now... I'm afraid to touch anything else, as I know what will happen — more heavy rewrites (I like writing). It's not that I don't want to do it, but I must do some other things first...