diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 4d983bf..7d5e6d6 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -1286,7 +1286,7 @@
 
 					*v:char* *char-variable*
 v:char		Argument for evaluating 'formatexpr' and used for the typed
-		character when using <expr> in an abbreviation |map-<expr>|.
+		character when using <expr> in an abbreviation |:map-<expr>|.
 
 			*v:charconvert_from* *charconvert_from-variable*
 v:charconvert_from
@@ -5773,6 +5773,8 @@
 		with name {name} when writing.  This uses the 'undodir'
 		option, finding directories that exist.  It does not check if
 		the undo file exist.
+		{name} is always expanded to the full path, since that is what
+		is used internally.
 		Useful in combination with |:wundo| and |:rundo|.
 		When compiled without the +persistent_undo option this always
 		returns an empty string.
diff --git a/runtime/doc/helphelp.txt b/runtime/doc/helphelp.txt
index 1787659..eea639f 100644
--- a/runtime/doc/helphelp.txt
+++ b/runtime/doc/helphelp.txt
@@ -273,6 +273,68 @@
 ==============================================================================
 3. Writing help files					*help-writing*
 
-TODO
+For ease of use, a Vim help file for a plugin should follow the format of the
+standard Vim help files.  If you are writing a new help file it's best to copy
+one of the existing files and use it as a template.
+
+The first line in a help file should have the following format:
+
+*helpfile_name.txt*	For Vim version 7.3	Last change: 2010 June 4
+
+The first field is a link to the help file name. The second field describes
+the applicable Vim version. The last field specifies the last modification
+date of the file. Each field is separated by a tab.
+
+At the bottom of the help file, place a Vim modeline to set the 'textwidth'
+and 'tabstop' options and the 'filetype' to 'help'.  Never set a global option
+in such a modeline, that can have consequences undesired by whoever reads that
+help.
+
+
+TAGS
+
+To define a help tag, place the name between asterisks (*tag-name*).  The
+tag-name should be different from all the Vim help tag names and ideally
+should begin with the name of the Vim plugin. The tag name is usually right
+aligned on a line.
+
+When referring to an existing help tag and to create a hot-link, place the
+name between two bars (|) eg. |help-writing|.
+
+When referring to a Vim option in the help file, place the option name between
+two single quotes. eg. 'statusline'
+
+
+HIGHLIGHTING
+
+To define a column heading, use a tilde character at the end of the line. This
+will highlight the column heading in a different color. E.g.
+
+Column heading~
+
+To separate sections in a help file, place a series of '=' characters in a
+line starting from the first column. The section separator line is highlighted
+differently.
+
+To quote a block of ex-commands verbatim, place a greater than (>) character
+at the end of the line before the block and a less than (<) character as the
+first non-blank on a line following the block. Any line starting in column 1
+also implicitly stops the block of ex-commands before it.  E.g. >
+    function Example_Func()
+	echo "Example"
+    endfunction
+<
+
+The following are highlighted differently in a Vim help file:
+  - a special key name expressed either in <> notation as in <PageDown>, or
+    as a Ctrl character as in CTRL-X
+  - anything between {braces}, e.g. {lhs} and {rhs}
+
+The word "Note", "Notes" and similar automagically receive distinctive
+highlighting.  So do these:
+	*Todo	something to do
+	*Error	something wrong
+
+You can find the details in $VIMRUNTIME/syntax/help.vim
 
  vim:tw=78:ts=8:ft=help:norl:
diff --git a/runtime/doc/if_mzsch.txt b/runtime/doc/if_mzsch.txt
index ca384cf..599552f 100644
--- a/runtime/doc/if_mzsch.txt
+++ b/runtime/doc/if_mzsch.txt
@@ -233,7 +233,7 @@
 ==============================================================================
 5. mzeval() Vim function				    *mzscheme-mzeval*
 
-To facilitate bi-directional interface, you can use |mzeval| function to
+To facilitate bi-directional interface, you can use |mzeval()| function to
 evaluate MzScheme expressions and pass their values to VimL.
 
 ==============================================================================
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 498df7f..63efd1c 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -7265,10 +7265,11 @@
 		set ul=0
 <	But you can also get Vi compatibility by including the 'u' flag in
 	'cpoptions', and still be able to use CTRL-R to repeat undo.
+	Also see |undo-two-ways|.
 	Set to a negative number for no undo at all: >
 		set ul=-1
 <	This helps when you run out of memory for a single change.
-	Also see |undo-two-ways|.
+	Also see |clear-undo|.
 
 						*'updatecount'* *'uc'*
 'updatecount' 'uc'	number	(default: 200)
diff --git a/runtime/doc/os_390.txt b/runtime/doc/os_390.txt
index 5a9d368..c39f3ba 100644
--- a/runtime/doc/os_390.txt
+++ b/runtime/doc/os_390.txt
@@ -7,7 +7,7 @@
 This file contains the particulars for the z/OS UNIX version of Vim.
 
 1. ASCII/EBCDIC dependent scripts	|zOS-has-ebcdic|
-2. Putty and Colors                     |zOS-Putty|
+2. Putty and Colors                     |zOS-PuTTY|
 3. Motif Problems			|zOS-Motif|
 4. Bugs					|zOS-Bugs|
 5. Limitations     			|zOS-limitations|
diff --git a/runtime/doc/pi_netrw.txt b/runtime/doc/pi_netrw.txt
index b57585b..e3032df 100644
--- a/runtime/doc/pi_netrw.txt
+++ b/runtime/doc/pi_netrw.txt
@@ -589,7 +589,7 @@
 PASSWORD						*netrw-passwd*
 
 The script attempts to get passwords for ftp invisibly using |inputsecret()|,
-a built-in Vim function.  See |netrw-uidpass| for how to change the password
+a built-in Vim function.  See |NetUserPass()| for how to change the password
 after one has set it.
 
 Unfortunately there doesn't appear to be a way for netrw to feed a password to
@@ -803,7 +803,7 @@
                                               get filename tempfile >
   ---------------------------------------------------------------------
 <
-The |g:netrw_ftpmode| and |g:netrw_extracmd| are optional.
+The |g:netrw_ftpmode| and g:netrw_extracmd are optional.
 
 Netrw then executes the lines above by use of a filter:
 >
diff --git a/runtime/doc/pi_vimball.txt b/runtime/doc/pi_vimball.txt
index 4928d11..8eaa838 100644
--- a/runtime/doc/pi_vimball.txt
+++ b/runtime/doc/pi_vimball.txt
@@ -197,7 +197,7 @@
 	     Apr 18, 2008 * RmVimball command is now protected by saving and
 	                    restoring settings -- in particular, acd was
 			    causing problems as reported by Zhang Shuhan
-	24 : Nov 15, 2007 * |g:vimball_path_escape| used by s:Path() to
+	24 : Nov 15, 2007 * g:vimball_path_escape used by s:Path() to
 	                    prevent certain characters from causing trouble
 	22 : Mar 21, 2007 * uses setlocal instead of set during BufEnter
 	21 : Nov 27, 2006 * (tnx to Bill McCarthy) vimball had a header
diff --git a/runtime/doc/tags b/runtime/doc/tags
index f2bf731..632f288 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -4293,14 +4293,11 @@
 OS2	os_os2.txt	/*OS2*
 OS390	os_390.txt	/*OS390*
 OS390-Motif	os_390.txt	/*OS390-Motif*
+OS390-PuTTY	os_390.txt	/*OS390-PuTTY*
 OS390-bugs	os_390.txt	/*OS390-bugs*
-OS390-building	os_390.txt	/*OS390-building*
-OS390-changes	os_390.txt	/*OS390-changes*
-OS390-feedback	os_390.txt	/*OS390-feedback*
 OS390-has-ebcdic	os_390.txt	/*OS390-has-ebcdic*
+OS390-limitations	os_390.txt	/*OS390-limitations*
 OS390-open-source	os_390.txt	/*OS390-open-source*
-OS390-weaknesses	os_390.txt	/*OS390-weaknesses*
-OS390-xterm	os_390.txt	/*OS390-xterm*
 OffTheSpot	mbyte.txt	/*OffTheSpot*
 OnTheSpot	mbyte.txt	/*OnTheSpot*
 Operator-pending	intro.txt	/*Operator-pending*
@@ -4890,6 +4887,7 @@
 cindent()	eval.txt	/*cindent()*
 cinkeys-format	indent.txt	/*cinkeys-format*
 cinoptions-values	indent.txt	/*cinoptions-values*
+clear-undo	undo.txt	/*clear-undo*
 clearmatches()	eval.txt	/*clearmatches()*
 client-server	remote.txt	/*client-server*
 clientserver	remote.txt	/*clientserver*
@@ -5984,6 +5982,7 @@
 help-writing	helphelp.txt	/*help-writing*
 help-xterm-window	helphelp.txt	/*help-xterm-window*
 help.txt	help.txt	/*help.txt*
+helpfile_name.txt	helphelp.txt	/*helpfile_name.txt*
 helphelp	helphelp.txt	/*helphelp*
 helphelp.txt	helphelp.txt	/*helphelp.txt*
 hex-editing	tips.txt	/*hex-editing*
@@ -8356,13 +8355,10 @@
 zOS	os_390.txt	/*zOS*
 zOS-Bugs	os_390.txt	/*zOS-Bugs*
 zOS-Motif	os_390.txt	/*zOS-Motif*
-zOS-building	os_390.txt	/*zOS-building*
-zOS-changes	os_390.txt	/*zOS-changes*
-zOS-feedback	os_390.txt	/*zOS-feedback*
+zOS-PuTTY	os_390.txt	/*zOS-PuTTY*
 zOS-has-ebcdic	os_390.txt	/*zOS-has-ebcdic*
+zOS-limitations	os_390.txt	/*zOS-limitations*
 zOS-open-source	os_390.txt	/*zOS-open-source*
-zOS-weaknesses	os_390.txt	/*zOS-weaknesses*
-zOS-xterm	os_390.txt	/*zOS-xterm*
 zR	fold.txt	/*zR*
 zW	spell.txt	/*zW*
 zX	fold.txt	/*zX*
diff --git a/runtime/doc/todo.txt b/runtime/doc/todo.txt
index 6f82a68..27039a2 100644
--- a/runtime/doc/todo.txt
+++ b/runtime/doc/todo.txt
@@ -1087,11 +1087,13 @@
    Ron's version: http://dev.ronware.org/p/vim/finfo?name=gvim.nsi
 - Also crypt the swap file, each block separately.  Change mf_write() and
     mf_read().
-    - How to get b_p_key to these functions?   Store it in mfp?
+    - How to get b_p_key to these functions?  -> Store buf_T pointer in mfp.
     - Generate a seed for the swapfile, put it in block 0.
     - For each block, use password + seed + byte offset to crypt/decrypt.
     - When changing the password need to read back with the old password and
       write again with the new one.
+    - Fill the gaps in the block with random bytes, otherwise it's easy to
+      check for correct password by finding NUL bytes.
     - Verify recovery works.
 - Update for crypt code to use salt. (Mohsin May 30)
     Make the strengthen_key value configurable and store it in the header?
@@ -1099,6 +1101,10 @@
 - undofile: keep markers where the file was written/read, so that it's easy to
   go back to a saved version of the file:  ":earlier 1f" (f for file)?
   Also add ":earlier 1d" (d for day).
+  Something like changenr() to see the "file saved" marker?
+  Show "file saved" marker in :undolist
+  Function to get undo tree: undotree().  List of lists.  Each entry is a
+  dictionary: {'nr': 2, 'time': 1234, 'saved': 1}
 - Create a helphelp.txt file, move instructions there to write help files from
   various.txt and list by Tony.
 Patches to include:
diff --git a/runtime/doc/undo.txt b/runtime/doc/undo.txt
index e8fed4f..6e2308f 100644
--- a/runtime/doc/undo.txt
+++ b/runtime/doc/undo.txt
@@ -314,6 +314,16 @@
 If it is zero, the Vi-compatible way is always used.  If it is negative no
 undo is possible.  Use this if you are running out of memory.
 
+							*clear-undo*
+When you set 'undolevels' to -1 the undo information is not immediately
+cleared, this happens at the next change.  To force clearing the undo
+information you can use these commands: >
+	:let old_undolevels = &undolevels
+	:set undolevels=-1
+	:exe "normal a \<BS>\<Esc>"
+	:let &undolevels = old_undolevels
+	:unlet old_undolevels
+
 Marks for the buffer ('a to 'z) are also saved and restored, together with the
 text.  {Vi does this a little bit different}