practice swings in the rough - sything the grass?

All good info...

I mustn't have been in deep enough rough to encounter any of this!

About the below:
"However, the player incurs no penalty if the action occurs:
• in grounding the club lightly when addressing the ball,
• in fairly taking his stance,"

Does this mean that if i ground my club "lightly" behind the ball in the rough and the ball then moves, that there is no penalty? Likewise with taking my stance? Or does that just refer to whatever is round about the ball and if the ball moves there is a penalty?

Thanks for your time. There's a lot to learn in this game!