Over the last years we’ve tried many techniques to make it easier to submit documentation for the Xfce packages. Unfortunately, whatever we’ve tried; hardly any documentation was contributed.
Complete documentation (or close to that) was still a goal for Xfce 4.10, so we’ve decided to drop the package manuals for the next stable release (now GIT master) and focus on a wiki-based setup. This means that the Help buttons in 4.10 will try to open your web browser and redirect you to the correct page on docs.xfce.org.
We understand a small group of people without Internet are affected by this change. However as the situation is right now, clicking the Help button is often not even possible and once the wiki is starting to grow, we’ll look into an xfce4-docs package that contains a snapshot of the wiki data.
We hope with this change the barrier to contribute manuals is low enough for contributors to help us with good documentation, so Xfce 4.10 will be the best documented release we’ve ever made (and that should fairly easy ;-).