What is the "0" in the effects commands for?

I’m just curious as to why the effect commands are phrased the way they are.As far as I can see the 0 is redundant,and doesn’t even show up in the pattern editor.So what’s the big secret I’m missing here?

If an effect starts with a 0 it’s a sample effect. If it starts with a Z it’s a global effect. If it starts with anything else it’s a device effect. Example, right click a parameter of any Renoise device and slide it around while holding the right click, you’ll see it insert a command into the pattern editor. You can use this for automation. This is most useful for automating devices on and off, and anything that you want to instantly snap to something. For smooth glides it’s generally better to use normal automation.