I just noticed that there is a conflict in the info provided about "stylesheet_directory" at two locations in the Codex. As far as I can tell, stylesheet_directory used to point to the parent theme stylesheet directory, but now points to the child stylesheet directory (if a child theme is active)
This page appears to be correct:
And this one appears to be wrong:
I don't think I know enough to edit these entries myself, so I'm hoping someone with more WP expertise will read this post and edit the Codex appropriately.