diff --git a/style/natbib.el b/style/natbib.el
index d56642c..7887ad8 100644
--- a/style/natbib.el
+++ b/style/natbib.el
@@ -1,6 +1,6 @@
-;;; natbib.el --- Style hook for the natbib package
+;;; natbib.el --- AUCTeX style for `natbib.sty' version 8.31b
 
-;; Copyright (C) 1997, 1998, 2004, 2007, 2014 Free Software Foundation, Inc.
+;; Copyright (C) 1997, 1998, 2004, 2007, 2014, 2016 Free Software Foundation, Inc.
 
 ;; Authors: Berwin Turlach <address@hidden>
 ;;          Carsten Dominik <address@hidden>
@@ -26,86 +26,132 @@
 
 ;;; Code:
 
-(TeX-add-style-hook "natbib"
- (function
-  (lambda ()
-    ;; The number in the cdr of the following list indicates how many
-    ;; optional note arguments we consider useful.  Prompting for those
-    ;; arguments will still depend upon `TeX-arg-cite-note-p'.
-    (let  ((citecmds
-	    '(("cite" . 0)
-	      ("citet" . 1) ("citet*" . 1) ("citealt" . 1) ("citealt*" . 1)
-	      ("citep" . 2) ("citep*" . 2) ("citealp" . 2) ("citealp*" . 2)
-	      ("citeauthor" . 0) ("citeauthor*" . 0) ("citefullauthor" . 0)
-	      ("citeyear" . 0) ("citeyearpar" . 0)
-	      ("shortcites" . 0))))
-
-      ;; Add these symbols
-      (apply
-       'TeX-add-symbols
-       (mapcar
-	(lambda (cmd)
-	  (cond
-	   ((= (cdr cmd) 0)
-	    ;; No optional arguments
-	    (list (car cmd) 'TeX-arg-cite))
-	   ((= (cdr cmd) 1)
-	    ;; Just one optional argument, the post note
-	    (list
-	     (car cmd)
-	     '(TeX-arg-conditional TeX-arg-cite-note-p (["Post-note"]) nil)
-	     'TeX-arg-cite))
-	   ((= (cdr cmd) 2)
-	    ;; Pre and post notes
-	    (list
-	     (car cmd)
-	     '(TeX-arg-conditional TeX-arg-cite-note-p ([LaTeX-arg-natbib-notes]) nil)
-	     'TeX-arg-cite))))
-      citecmds))
-
-      ;; Add the other symbols
-      (TeX-add-symbols
-       '("citetext" "Text")
-       '("bibpunct" ["Post note separator"]
-		 "Opening bracket"
-		 "Closing bracket"
-		 "Punctuation between multiple citations"
-		 "style [n]umeric [s]uperscript [a]uthor-year"
-		 "Punctuation between author and year"
-		 "Punctuation between years for common authors")
-       '("citestyle" "Style")
-       '("citeindextrue")
-       '("citeindexfalse")
-       '("citeindextype"))
-
-      ;; Make an entry in TeX-complete-list
-      (add-to-list
-       'TeX-complete-list
-       (list
-	(concat "\\\\\\("
-		(mapconcat (lambda (x) (regexp-quote (car x)))
-			   citecmds "\\|")
-		"\\)\\(\\[[^]\n\r\\%]*\\]\\)*{\\([^{}\n\r\\%,]*,\\)*\\([^{}\n\r\\%,]*\\)")
-	4 'LaTeX-bibitem-list "}")))
-
-    ;; Fontification
-    (when (and (fboundp 'font-latex-add-keywords)
-	       (eq TeX-install-font-lock 'font-latex-setup))
-      (font-latex-add-keywords '(("cite" "*[[{")
-				 ("citet" "*[[{")
-				 ("citealt" "*[[{")
-				 ("citep" "*[[{")
-				 ("citealp" "*[[{")
-				 ("citeauthor" "*[[{")
-				 ("citefullauthor" "[[{")
-				 ("citeyear" "[[{")
-				 ("citeyearpar" "[[{")
-				 ("shortcites" "{"))
-			       'reference))
-
-    ;; Tell RefTeX
-    (if (fboundp 'reftex-set-cite-format)
-	(reftex-set-cite-format 'natbib))))
+(TeX-add-style-hook
+ "natbib"
+ (lambda ()
+   ;; The number in the cdr of the following list indicates how many
+   ;; optional note arguments we consider useful.  Prompting for those
+   ;; arguments will still depend upon `TeX-arg-cite-note-p'.
+   (let  ((citecmds
+	   '(("cite" . 0)
+	     ("citet" . 1) ("citet*" . 1) ("citealt" . 1) ("citealt*" . 1)
+	     ("citep" . 2) ("citep*" . 2) ("citealp" . 2) ("citealp*" . 2)
+	     ("citeauthor" . 0) ("citeauthor*" . 0) ("citefullauthor" . 0)
+	     ("citeyear" . 0) ("citeyearpar" . 0)
+	     ("shortcites" . 0)
+	     ;; 2.4 Extended Citation Commands
+	     ("citenum" . 0)
+	     ;; 2.5 Forcing Upper Cased Name
+	     ("Citet" . 1) ("Citet*" . 1) ("Citealt" . 1) ("Citealt*" . 1)
+	     ("Citep" . 2) ("Citep*" . 2) ("Citealp" . 2) ("Citealp*" . 2)
+	     ;; 2.6 Citation Aliasing
+	     ("citetalias" . 1) ("citepalias" . 2))))
+
+     ;; Add these symbols
+     (apply
+      'TeX-add-symbols
+      (mapcar
+       (lambda (cmd)
+	 (cond
+	  ((= (cdr cmd) 0)
+	   ;; No optional arguments
+	   (list (car cmd) 'TeX-arg-cite))
+	  ((= (cdr cmd) 1)
+	   ;; Just one optional argument, the post note
+	   (list
+	    (car cmd)
+	    '(TeX-arg-conditional TeX-arg-cite-note-p (["Post-note"]) nil)
+	    'TeX-arg-cite))
+	  ((= (cdr cmd) 2)
+	   ;; Pre and post notes
+	   (list
+	    (car cmd)
+	    '(TeX-arg-conditional TeX-arg-cite-note-p ([LaTeX-arg-natbib-notes]) nil)
+	    'TeX-arg-cite))))
+       citecmds))
+
+     ;; Add the other symbols
+     (TeX-add-symbols
+      '("citetext" "Text")
+      '("bibpunct" ["Post note separator"]
+	"Opening bracket"
+	"Closing bracket"
+	"Punctuation between multiple citations"
+	"style [n]umeric [s]uperscript [a]uthor-year"
+	"Punctuation between author and year"
+	"Punctuation between years for common authors")
+      '("citestyle" (TeX-arg-eval completing-read
+				  (TeX-argument-prompt optional nil "Style")
+				  '("plain" "plainnat" "agu" "egu"
+				    "agms" "dcu" "kluwer" "cospar" "nature")))
+      '("citeindextrue")
+      '("citeindexfalse")
+      '("citeindextype")
+      '("defcitealias" TeX-arg-cite "Alias")
+      '("setcitestyle" (TeX-arg-key-val
+			(;; Citation mode (fourth argument of \bibpunct):
+			 ("authoryear") ("numbers") ("super")
+			 ;; Braces (first and second arguments of \bibpunct):
+			 ("round") ("square") ("open") ("close")
+			 ;; Between citations (third argument of \bibpunct):
+			 ("semicolon") ("comma") ("citesep")
+			 ;; Between author and year (fifth argument of \bibpunct):
+			 ("aysep")
+			 ;; Between years with common author (sixth argument of \bibpunct):
+			 ("yysep")
+			 ;; Text before post-note (optional argument of \bibpunct):
+			 ("notesep")))))
+
+     ;; Make an entry in TeX-complete-list
+     (add-to-list
+      'TeX-complete-list
+      (list
+       (concat "\\\\\\("
+	       (mapconcat (lambda (x) (regexp-quote (car x)))
+			  citecmds "\\|")
+	       "\\)\\(\\[[^]\n\r\\%]*\\]\\)*{\\([^{}\n\r\\%,]*,\\)*\\([^{}\n\r\\%,]*\\)")
+       4 'LaTeX-bibitem-list "}")))
+
+   ;; 2.12 Other Formatting Options
+   (TeX-add-symbols
+    "bibsection"
+    "bibpreamble"
+    "bibfont"
+    "citenumfont"
+    "bibnumfmt")
+   (LaTeX-add-lengths "bibhang" "bibsep")
+
+   ;; Fontification
+   (when (and (fboundp 'font-latex-add-keywords)
+	      (eq TeX-install-font-lock 'font-latex-setup))
+     (font-latex-add-keywords '(("cite"		  "*[[{")
+				("citet"	  "*[[{")
+				("citealt"	  "*[[{")
+				("citep"	  "*[[{")
+				("citealp"	  "*[[{")
+				("citeauthor"	  "*[[{")
+				("citefullauthor" "[[{")
+				("citeyear"	  "[[{")
+				("citeyearpar"	  "[[{")
+				("shortcites"     "{")
+				("citenum"        "{")
+				("Citet"	  "*[[{")
+				("Citealt"	  "*[[{")
+				("Citep"	  "*[[{")
+				("Citealp"	  "*[[{")
+				("Citeauthor"	  "*[[{")
+				("citetalias"	  "*[[{")
+				("citepalias"	  "*[[{"))
+			      'reference)
+     (font-latex-add-keywords '(("defcitealias"   "{{")
+				("bibpunct"	  "[{{{{{{")
+				("setcitestyle"   "{")
+				("citestyle"	  "{"))
+			      'function))
+
+   ;; Tell RefTeX
+   (if (fboundp 'reftex-set-cite-format)
+       (reftex-set-cite-format 'natbib)))
  LaTeX-dialect)
 
 (defun LaTeX-arg-natbib-notes (optional)