NPR's Brooke Gladstone reports on the long-awaited television rating system, which was unveiled today. A TV industry group chose an age-based plan that child advocates say doesn't give parents enough specific information about a program's sexual or violent content. The proposed six-tiered system is designed to work with the so-called "V-chip" to allow parents to block unwanted shows. The ratings plan is subject to approval by the Federal Communications Commission. President Clinton thanked the industry group that came up with the voluntary plan and said it will be up to parents and child advocates to use, evaluate and comment on the system's effectiveness, once it's implemented.