WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: PDFs and NVDA


From: Karlen Communications
Date: Aug 22, 2011 6:12AM

OK, found the NVDA keyboard command and headings are being listed in my PDF
documents. Can you send me the sample Word and PDF documents to look at off

Cheers, Karen

-----Original Message-----
[mailto: <EMAIL REMOVED> ] On Behalf Of Karlen
Sent: August-22-11 6:33 AM
To: 'WebAIM Discussion List'
Subject: Re: [WebAIM] PDFs and NVDA

The recommended "reading order" is to infer the reading order from the
document. This is what Acrobat or Reader should be set at by default in the
Reading category of the Preferences. Tab Order only comes into play for
forms or PDF documents with links. This is the only time we have the option
to "Tab" through content and the content being tabbed through are the form
controls and the links not the "regular text" of the document. Any document
without links or form controls we use standard navigation/reading keyboard
commands for moving through documents.

The other two options, left to right, top to bottom and the raw print
stream are used for legacy or untagged PDF documents and are meant to be an
option in getting some kind of sense out of the document when the
recommended reading order doesn't work with the PDF. These are options even
if the PDF is tagged but not tagged properly. Duff is correct in that Tags
are what makes a PDF accessible and these other two options are considered
to be last resorts when the document is not tagged...or as I've said, not
tagged correctly.

I have NVDA and opened a PDF tagged from Word in Acrobat 9. When I press H
NVDA does move from heading to heading in the document. I couldn't find
reference to the keyboard command to list headings in NVDA...am a JAWS user.
Can you send the keyboard command and I'll see if it works with my
documents? My first thought was that NVDA didn't have this feature for PDF
documents which is why you got an empty list or no list at all. I did try to
find a list of the keyboard commands for NVDA but the WebAIM link which
seems to be the best match to the search results won't open and all other
references don't mention listing headings as a feature of NVDA. Will keep
trying but if you have the keyboard command that would be helpful.

Cheers, Karen

-----Original Message-----
[mailto: <EMAIL REMOVED> ] On Behalf Of LSnider
Sent: August-21-11 7:52 PM
To: WebAIM Discussion List
Subject: Re: [WebAIM] PDFs and NVDA

Hi Duff,

Yes, headings was correct LOL.

I asked about the reading order differences in Acrobat/Reader because I
always thought there was a default reading order that would help screen
readers. What confused me was that I had to set it to tabbed reading order
in my version of Acrobat, as it wasn't the default for my Acrobat 9 program.
It seems like it would be better to have that as the program default, but I
am sure there is a reason why it was done that way.

I hadn't realized that about other PDF programs, good to know. I have used
Acrobat since it was created and always liked it best, so I don't use the
others much unless a client asks for it.

Yes I played with Word a lot over the years and in 2007 (I am going to
install 2010 next week) I like the fact that you can create PDFs that are
already tagged, nice feature.

Okay, that is what I thought about the tagging, so thanks for confirming
that for me.

Very good reasons for tagging, and thanks for the information on the touch
up tool. I strive for good source documents, so good to know that is the way
to go.

Thanks again!



On Sun, Aug 21, 2011 at 2:42 PM, Duff Johnson < <EMAIL REMOVED> > wrote:

It's not that "most people" use the tagged reading order... it's that tags
> are the ONLY place for logical structure, which is vital to the
> reliable reading and navigation of a PDF using AT. That said, many
> (most) applications OTHER than Adobe's are unable (at this time) to
> create or process tags in a PDF. Microsoft Office supports tagged PDF
> generation from Word files, and so does Open Office.
> Key point: The tags COME FROM the headings (not "headers", per Bevi).
> Software that supports creation of accessible PDFs from the source
> file will convert the structures present in the source file into
> corresponding PDF tags. So, exactly as you surmise... use good
> structures in your source file, and you have the right to expect a
matching structure in your PDF.
> PDFs generated by software that does not support tagged PDF for output
> may be handled for accessibility purposes in two basic ways.
> 1) The "raw print stream" (PDF name is "reading order" - see earlier
> threads). In practice, this is what most software reads instead of the
> The results range from "so-so" on extremely simple documents to
> "chaotic" in other cases.
> 2) Some interpretation of the raw print stream using other
> information (page-position, font size, font choice, etc, etc).
> It should be noted that both of the above approaches are totally
> illegitimate with respect to accessibility. There is only one option
> that can comply with WCAG 2.0 - support for tagged PDF in all its
> Yes... some users get good use from software that (primarily) uses
> reading order (cell phones, for example), but that's simply an example
> of something being better than nothing.
> That tool tweaks BOTH the raw print stream order (content order) AND
> the tag order. While this is not an unreasonable thing to do in the
> right circumstances, execution is everything, and I do not recommend
> the use of this tool in its current manifestation for this purpose.
> The first part... focus on getting the source file as good as possible
> so that tweaking in Acrobat or with other tools is minimized... is
> exactly correct.
> Otherwise... all the fixup following file creation can generally be
> done in the tags panel. Some of the Touch Up Reading Order Tool
> elements can be handy, but it's not a great tool, sorry to say.
> Duff Johnson
> p +1.617.283.4226
> t http://www.twitter.com/duffjohnson
> w http://www.duff-johnson.com