VSC (Vertical Speed Conservation)
A common glitch in ABC. The moment when you land after a recover, a lava bounce, a ground pound or a bounce of ZB or butt slide (with 0 speed or less), Mario's vertical speed will be the same as his vertical speed on the previous frame. For example, if you start a recover from a certain height and you land on the same height, you will have a VSC of -34. This means that if you leave the platform, you will start falling from -34 instead of from 0. You can also keep it by standing still, punching or crouching. This means that also moving resets his speed to 0. As for useful application of it, you can conserve a VS of 26 (first frame of a recover), that way you can leave a platform with 26 vertical speed and not only get the same height as a recover, but also have access to ledge grab.
26 VSC + Grab on covers a height of 247
Examples of the trick:
In this last video negative VSC is used instead, since you need to get to the elevator (by falling down) fast.
Star Dance Clip (SDC)
Another common glitch in ABC. Normally, all of Mario's jumps' vertical speed decrease 4 by 4, but if you collect a star in air you will end up decreasing vertical speed 3.2 by 3.2 (and you will also get on the wanted platform if you get close to it Because the game consider it like a normal jump you can use to grab ledges!)
DR + Star Dance Clip (by getting star first frame possible after recover) covers a height of 298.
These are the most notable examples of the trick: