[Silvuh]

For 12th notes, you could add that, because stepcharts are written in 4/4 time, 12th notes carry the beat when you step a waltz or anything in 3/4 time. They also occur when 12th swing is used in 4/4 time.

Originally Posted by rushyrulz

... 192nd notes, but for the most part, they're the same thing as 4th notes.

Should say that they're basically the same thing as the note they're closest to, because they're not always right next to 4ths.
You could also add that 192 is 12 * 16, which may make them easier to visualize.
(FFR being 1/30 seconds per frame, any two notes 192nd apart will likely be on the same frame at any faster than 37.5 beats per minute.)