* doc/emacs/modes.texi (Choosing Modes): auto-mode-case-fold is now t.
* doc/lispref/modes.texi (Basic Major Modes): New node. Callers updated.
(Major Modes): Document fundamental-mode and major-mode.
(Major Mode Basics): Node deleted; text moved to Major Modes.
(Derived Modes): Document derived-mode-p.