From Fedora Project Wiki

I'm working at the University of Newcastle upon Tyne, UK; evaluating Xen in FC4 for providing a secure virtual hosting service. I complained about some innaccuracies in the FedoraXenQuickstart page and the result was being added to the EditGroup :-) I will most likely be making changes there, perhaps some small corrections in other places. You can reach me via jon@dowland.name

FedoraXenQuickStart change: the su -c stuff

Someone modified all the commands on the page that required root priviledges to be su -c '...'. This was really nasty and horrible so I changed it to prefixing such commands with '#' and explaining the convention in the preamble.

Problems with the su -c '..' approach: it precludes those systems where users get root via sudo or another mechanism; it forced the author to compress commands to be readable on one line (the net result being the command was more opaque); there were some commands that needed root omitted and others that didn't need root needlessly using it.