overscan in hdtv: how is it done ?

Archived from groups: alt.tv.tech.hdtv (More info?)

I am just wondering how the overscan is currently handled in the newer
digital tv (plasma/lcd). With the older analog tv of 425 lines you loose
around 20 lines to overscan so you were really looking at a picture that
has 405 to 410 lines on screen.

With the newer tv that has let say 720 of physical pixel lines, does the
broadcast station transmit something like 736 lines (assuming 5%
overscan) and we are only seeing 720 ?