Three guys from the forum here have pioneered the application and looking at their work, the system can be more easily understood.
At the bottom of this page there is a table containing links to 5 different users. It includes 2 publications and 3 individuals.
http://www.cactiguide.com/custom_nomenclature/
I am sorely behind with setting the publication data, which will be a lot more helpful when completed than it is now.
For Peter, you can see how he has broken up "Sclerocactus" and when logged into his system, you'll see Ancistrocactus, Glandulicactus, and Toumeya on the Genus list on the left!
Then go back to the nomenclature page and click on Kyle Barker. He has done a nice job with the genus Lophophora. Click on this genus on the menu and you'll see lots of helpful info on the genus page and under each species.
Sullyman give a nice treatment of Coryphantha. Select his name and be sure to go to his home page for an overview of the Genus. Then click on Coryphantha on the menu and see more notes on the genus page as well as notes on various species such as:
clavata subsp. stipitata
cornifera f. maliterrarum
delaetiana
Anyway, I invite you to explore some of the above systems. Hopefully, I will be able to get more work done on the publications soon.
Edit: To get to the table with the various links, just click on the brown bar at the top of any page of the main site (not forum) and click on the link that says "About this".
Daiv