Raw commands, predefined commands, opus helper etc

This post also excited by this one:
[url]Refresh folderalias.oxc]

I am interested in clarifying a few terms. I have an idea of what they are but rather than pollute a potentially useful reference post I am not going to detail my understanding:

Raw commands:
Predefined commands:
Internal commands (Summary in Help appendix. Looks to be combination of both the above?):

Also a few executables (at least one of which I have reason to believe is associated with one or more of the terms above.
See [url]Alternative filetypes to DCF]):


With reference to the other post referred to above, I am interested in this point:

The "/restart" command is used here as a direct switch to dopusrt.exe. This switch seems to be referenced within the "Close" Raw command as a follow on to the "SYSTEM/O" switch. A similar reference is made in the Appendix > Internal Commands summary. This does not seem consistent to me.

Finally there is this facility.

What exactly is this called? What is it's relationship to the terms above?