As a general rule the spiffchorder is using the standard key-bindings were possible. This is a benefit as most of you are coming to chording already familiar with the QWERTY keyboard. As such prefixing a chord with Shift does what you would expect, Shift+] generates }, Shift+3 generates # and so on.
There are lots of chord possibilities, if you look at the nasa_us.h1) file you notice many lines beginning with KEY__, these are as yet unassigned chords. You can add key bindings to these unused chords or remap the entire set if you choose.2) By default in this chordset there are sometimes several chords that will generate the same key. For example, there are at least 2 ways to get a Question Mark ?, you don't need to learn both, just the one that works for you.3)
There are a number of ways to think about the chords, usually one will make the most sense to you. Our primary method of describing and charting the chords is explained in the first lesson: Lesson 1 - Reading the Charts and Chording Basics. Working through the lessons will get you familiar with the chords and concepts you will need to become proficient on the spiffchorder. Even if you plan on building you own chordset, it might be worth looking over the lessons. In addition to the lessons the complete bound chords for this chordset is also available as 4 charts: