We've all been there. We're looking at a site and keep refreshing to see if what we're looking for has been updated. But, often times our browsers will cache items on the page (especially images and Flash™ documents.) This enables faster page loads, and less data transfer, which is actually nice. However, if you're a web developer, or someone who checks the tips site a lot for comments, you want to know that the information you're viewing is perfectly accurate. And, you don't want to empty your cache every time you look at a site. So, here's what you do. To get a page to refresh, and not draw from a cache, simply put a good old-fashioned question mark (?) at the end of your URL, and hit "Enter."
I think it's more of a self exploratory, what does it mean to you, kind of tip.
May be the take away is: "If you're ever held hostage and they're going to kill you if you can't draw a 6 with your hand while moving your foot clockwise. You should draw the six from the bottom up and you'll be safe."