Couldn't find a forum section that specially deals with documentation in general--or did I miss something?
The Codex post for function register_sidebars() has a code example ("Default Usage") that for a couple of reasons doesn't work as desired if you just copy/paste it:
you get notices for undefined variables, the ID for multiple sidebars would be the same and the sprint_f-wrapper function seems to be impractical, too (which is actually mentioned in the parameter description underneath – I don't understand though why it it used then anyway).
I find this rather confusing but failed to come up with a better code example and hence didn't edit anything. Perhaps someone more skilled can take care of it?