What was that sticker that came with old graphic cards?

Hello,

In the not too distant past, like 10 years ago, when I bought a GF2-4 card, Riva TNT or Riva TNT2 card, the manufacturer included this blue sticker (with square boxes) which you stick it on your screen to calibrate the colour displayed I think. It reminds me of TV test cards. What was that sticker called? Is it still in use now, because most of us are using LCD's, but CRT's are still being used though I don't see sticker being included anymore. Is there any more functions of that sticker now days? Does it have the same function as the TV test cards? Looking back, if I were to do it now, kids would think that is one bizarre way of configuring your screen.

Thanks.