BTW, what ever happened to that call? I haven't seen a referee call that in years. I've seen the high/low called, but I think it's unnecessary roughness.
Clipping is actually a block in the back below the waist, but you’re right, you don’t see it called that much anymore, it’s usually a block in the back.
If you watch some of the clip shows on NFL Network, you’ll notice 40 or so years ago, defenders would wrap around the waist where as today, you see alot more of defenders hitting in the upper chest/head.