I hope Red puts up a couple of really simple examples on how to build DSLs. It's one of the great things Red/Rebol has to offer, but it isn't obvious how to do it.
[1]: https://github.com/red/red/wiki/Red---Rebol-Dialects:--Selec...
With that said, I would appreciate if you'd listed what would you like to see in "How to bake DSL with Parse" guide of some sort, that would be really helpful when the time will come for writing tutorials and documentation.