Index: latex.el
===================================================================
RCS file: /sources/auctex/auctex/latex.el,v
retrieving revision 5.482
diff -u -r5.482 latex.el
--- latex.el	28 Jan 2013 08:35:44 -0000	5.482
+++ latex.el	28 Jan 2013 12:36:40 -0000
@@ -5178,6 +5178,11 @@
   :type '(repeat regexp)
   :group 'TeX-command)
 
+(defvar LaTeX-header-start 
+  (concat "^[^%\n]*" (regexp-quote TeX-esc) "document\\(class\\|style\\)\\([[^]+]\\)?"
+          "\\({[^}]+}\\)")
+  "Default start of header marker for LaTeX documents.")
+
 (defvar LaTeX-header-end
   (concat "^[^%\n]*" (regexp-quote TeX-esc) "begin *"
 	  TeX-grop "document" TeX-grcl)
@@ -5224,6 +5229,7 @@
       (setq LaTeX-largest-level (LaTeX-section-level "section")))
 
   (setq TeX-header-end LaTeX-header-end
+        TeX-header-start LaTeX-header-start
 	TeX-trailer-start LaTeX-trailer-start)
 
   (require 'outline)