How does the automatic commercial advance on my VCR work?

Question

My VCR has this feature that automatically skips the commercials when I record programs. It doesn't always work, but when it does, its pretty cool. Anyone know how this little feature works?

Answer 1

When you engage Commercial Advance during recording, the VCR inserts electronic markers on the tape at the beginning and end of each station break. During playback, the VCR detects the markers and automatically fast-forwards through the commercials.