From the Book's Introduction:
Welcome to the STOCS lite companion. This is a flesh-tearing, excitement explosion of new rules and systems for STOCS lite. A massive bundle of presents for the STOCS lite aficionado (and people who like tanks).
Everything in here is optional, you don't need to use all (or even any) of these rules to run a good STOCS lite game. Take what you like the look of, ignore sections that deal with things you'll never need and come up with your own modifications. We want you to play with a system that you're completely happy with, that's why we constantly strive to make our rules simple and flexible.
Some of the highlights of the contents are as follows:
A new points based system for generating character attributes, which will please all those people who hate randomness in character generation.
Character generation expansions such as character age, wealth and attribute based skills.
A new and improved skill list, rules for team tasks and rules for long term tasks.
Additional melee and bow combat rules suitable for medieval games. New firearms rules including dealing with heavy weapons like tank guns and artillery.
A magic system which can be used for any sort of campaign which contains supernatural abilities like magic (or psionics or super powers).
Finally a system for dealing with vehicles of all types, including special rules for pursuits (that's car chases for you action movie fans).