Great explanation except every time I make a rom I get error in CWM
Tip: it doesnt matter if I mod it or not as soon as it changes update-script it screws the rom up I think and I even converted it back to updater-script when I was done still nothing.
It was an ICS rom if that helps.
use winrar but dont extract go in and delete update-script, and update-binary it will make you one that works.
recommend it anyways because it unclutters your scripts