Note: To get the RVK sliders (in the action window) you have to have the ‘relative keys’ button pressed in the animation buttons. I think you also have to have your keys selected in the IPO window,…AND!..if you are not seeing the elusive little triangle (the button that calls up the sliders) in the action window yet, you may have to toggle back and forth between the IPO and the Action window before it appears. then click it, and pull up the slider for the selected key! yippee!
what exactly are they?
RVK sliders let you set the relative values of your RVKs in the action window by adjusting the sliders to the desired levels and making a keyframe. If you haven’t fooled with RVKs Hos’s tutorial on the BlenderChar website is a good place to start. Hey thanks for the set smooth tip btw, seems to work well for alot of situations.
No worries… er… what exactly is RVK? 
This was true in old Blender,
now at the first Key you store Blender asks you if
you want an Absolute or a Relative Key.
Pretty strange behaviour!
Stefano
There are yet alot of gray areas in my RVK understanding. It’s like, I can pretty much get them to behave as I want them to most of the time, with some effort, but I don’t really understand how I am getting there yet. Know what I mean? At some point, I will probably bonk myself on the head, and say “duhhhhh, why did it take me so long to comprehend this?”
Also: RVK stands for “Relative Vertex Key”
I’ve updated the RVK part of the manual yesterday, but it won’t be online untill next monday 
Hold on.
Stefano
Awesome, I look forward to reading it.
You can anyway download the XML & images from the CVS, go to www.belnder.org and projects to access the CVS.
Stefano