In perusing <http://dev.w3.org/csswg/css3-writing-modes>, I ran into a broken link, so I ran it through the link checker, and it found these broken links:

http://dev.w3.org/Style/
  Line: 147
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

http://dev.w3.org/csswg/css3-writing-modes/logical-directions
  Line: 1850
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

http://dev.w3.org/csswg/css3-writing-modes/line-directions
  Line: 1857
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

http://dev.w3.org/2004/01/pp-impl/32061/status
  Line: 151
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

http://dev.w3.org/Style/CSS/members
  Line: 146
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

http://dev.w3.org/Consortium/Patent-Policy-20040205/

 Lines: 149, 155, 157
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.
Fragments:
        def-essential                   Line: 155
        sec-Disclosure                  Line: 157

http://www.w3.org/Style/CSS/Tracker/products/FIXME
  Line: 65
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

http://dev.w3.org/csswg/css3-writing-modes/abstract-dimensions
  Line: 1868
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

http://dev.w3.org/csswg/css3-writing-modes/logical-to-physical
  Line: 2084
  Code: 404 Not Found
 To do: The link is broken. Double-check that you have not made any typo,
        or mistake in copy-pasting. If the link points to a resource that
        no longer exists, you may want to remove or fix the link.

(It also mentioned some mailto: addresses that it didn't check, and something on unicode.org that it said was excluded by robots.txt, but which I checked and works, *and* that you left the trailing slash off of your links to several other specs, leading to an extra round-trip between client and server...)

Additionally, the HTML validator found this problem:

Line 1742, Column 27: duplicate specification of attribute "CLASS"
  <div class=figure class=data id=fig-text-orientation>
You have specified an attribute more than once. Example: Using the "height" attribute twice on the same "img" tag.