What's with this "Shoot to the right"

I have not done much with RAW but I am thinking of playing a little more with it and with HDR. In a lot of information that I have read, they are talking about "shooting to the right". Can someone please explain what this means?

My interpretation is that the image should be slightly overexposed. This is contrary to my understanding where with digital (as with transparency) slightly underexposing gives better DR and saturation. Are people saying that more detail is retrievable from RAW images that are slightly overexposed than those that are slightly underexposed. That is that more detail can be taken from blown highlights than darker areas.

Sorry for the basic question but would appreciate some clarification from the experts.
Thanks in advance.