The transition from Tkinter/tkinter to tkinter/_tkinker in 3.x docs is
incomplete.

1. There are several places not in titles or beginning of sentences
where Tkinter (roman type) needs to be replaced with tkinter (fixed
type, as elsewhere).

2. "24.1.1. Tkinter Modules
Most of the time, the tkinter is all" <<delete 'the' before tkinter>>

24.1.6.4. Coupling Widget Variables
 "from a class called Variable, defined in the tkinter." ditto

3. 24.1.5. How Tk and Tkinter are Related
"tkinter (C) 
These commands and their arguments will be passed to a C function in the
tkinter - note the lowercase - extension module"
Change 'tkinter' to '_tkinter' and 'lowercase' to 'underscore'.

"Xlib (C) 
the Xlib library to draw graphics on the screen. "

Is this still true? Or does Tk now use native libraries?

Not 3.x specific.

10. "Specifically, the man pages in the mann directory are most useful."
Is 'mann' literally correct? a typo? or meant to mean 'man#', where # is
a digit? If the last, either man# or mann with the last 'n' a different
font would be clearer to me.

This is, of course, *nix specific.

11. "Credits:
Tkinter was written by Steen Lumholt and Guido van Rossum. 
Tk was written by John Ousterhout while at Berkeley. "
Except for the first two lines, the entries are in historical order, so
I would reverse the first two.
 
12. 24.1.6.6. Tk Option Data Types
"To specify an X bitmap filename, give the full path to the file,
preceded with an @, as in "@/usr/contrib/bitmap/gumby.bit"."
*nix only? what about windows .bmp file?

13. (ttk section) 24.2.3.1. Standard Options
"0, 1 or an empty is return." => "0, 1 or an empty string is returned."


PS. I like the colors of the option-description tables.

A somewhat separate issue is the lack of even a mention of the existence
of the Canvas widget, which would merit a separate subsection if
documented. I think it should at least be mentioned with a reference to
the online reference materials listed before.

Indeed, the tkinter reference should somewhere have a complete list of
widgets, just like the ttk section does

24.2.2. Ttk Widgets¶

Ttk comes with 17 widgets, eleven of which already existed in tkinter:
Button, Checkbutton, Entry, Frame, Label, LabelFrame, Menubutton,
PanedWindow, Radiobutton, Scale and Scrollbar. The other six are new:
Combobox, Notebook, Progressbar, Separator, Sizegrip and Treeview. And
all them are subclasses of Widget.

This "The authors strongly suggest getting a copy of the Tk man pages. "
should be followed by a mention that they are available at the active
state site, in particular, at http://www.tcl.tk/man/tcl8.5/

Here is an incomplete patch. I fixed all the markup errors, typos and
similar issues you mentioned and a few more that I noticed.

Someone that knows Tkinter better than me should take care of the
remaining issues, i.e.:
 * is Xlib still used?
 * bmp files on Windows
 * the section about Canvas

3.x specific issues:

1. In most of the places I think it's OK to use 'Tkinter' and use
:mod:`tkinter` only when referring specifically to the module. I also
fixed other :mod:`Tkinter` around in the Doc.

2. Both fixed.

3. Fixed. I also changed *tkinter* to :mod:`tkinter`. I don't know about
Xlib.

Not 3.x specific:

> 10. "Specifically, the man pages in the mann directory are most 
> useful."
> Is 'mann' literally correct? a typo? or meant to mean 'man#', where # 
> is a digit?

I used 'manN' and added the link you provided (even if right now the
site seems down so I can't verify if it's correct).

> 11. "Credits:
> Tkinter was written by Steen Lumholt and Guido van Rossum. 
> Tk was written by John Ousterhout while at Berkeley. "
> Except for the first two lines, the entries are in historical order, 
> so I would reverse the first two.
 
Done.

> 12. 24.1.6.6. Tk Option Data Types
> "To specify an X bitmap filename, give the full path to the file,
> preceded with an @, as in "@/usr/contrib/bitmap/gumby.bit"."
> *nix only? what about windows .bmp file?

Does someone know the answer?

> 13. (ttk section) 24.2.3.1. Standard Options
> "0, 1 or an empty is return." => "0, 1 or an empty string is 
> returned."

Fixed.

> PS. I like the colors of the option-description tables.

Thank Raymond for them.

Since there's no activity on this issue I committed the patch in r78950 (py3k) and r78951 (release31-maint).
I'm leaving the issue open and assigning it to Guilherme because there are still a few thing missing (see previous message).

> I used 'manN'
FYI, there is a :file:`man{n}` construct where braces mark up replaceable text, like the var element in HTML.