Is it okay to drop my tip out beds at rest stops or Walmart?

Interesting that the "Walmart Rules" posted here may allow RV "parking". Doesn't say a thing about "camping". I think that many of the posts here are to discourage setting up camp in the Walmart parking lots. We all would like to be able to stop and catch some zzzzzz's if we had no other choice, and I for one only hope that walmart doesn't change their policy when RVers take advantage of the hospitality and set up camp just to avoid paying for a stay at a nearby park.