Actually, the question someone had was about trimming their core, and they wanted to know what kind of ab exercses to do. Since much of whether or not you can see a trim waist depends not on the muscle tone of the abs, but on the reduction of fat covering the muscles, I suggested that the person concentrate not just on ab work, but on exercises that engage large muscle groups, and which burn more fat. Squats and deadlifts are the exercises that use the most amount of muscle. I was referring to full deadlifts, which engage even more muscle groups that the 1/4 deadlifts. This doesn't mean that the 1/4 deadlifts won't help.
I probably gave a better description of it in another thread (it's the end of the day on Friday, when I'm not know for lucidity!) but I'll try again here (you can search for the other thread as well).
Start with the barbell on the floor. It's best to use bigger end plates, as they make the bar higher off the ground so it is easier to pick up. Stand with toes under the bar, with feet about hip-width apart. Bending from the knees and hips (not the waist), and keeping the chest up and the shoulder blades back and down, pick up the bar. Then drive yourself up through the heels, always thinking about leading with the chest (as if there is a rope attached to your sternum that is pulliing you toward the ceiling).
This is an advanced move, and can be risky if done incorrectly. At no time during this move should your back round or overarch (rounding is definitely more hazardous). You can work up to quite heavy weights.
If you want to try these, I recommend starting with VERY light weights.
If you can't keep a straight back while doing this move, don't do it! Or you can try modifying by setting the bar on some step risers, so that the weight plates sit down into the hollow part of the risers. That will bring the bar up a bit higher.
When I worked out in a weight room and did heavy squats and deadlifts (and barely any isolated ab work, though I'd do it now for core strength)my abs got much leaner.