I'm about to start a SR campaign. All players are going to use NSRCG to create characters. The software allows players to use Flaws & Edges, but I can't find any explanation of them either in the main rulebook, CC, M&M, or MITS. Where are the rules for Flaws & Edges?

The flaws and edges are in the Shadowrun Companion, a book I acquired just two days ago. Thats about it...