Adobe Acrobat XI - Manual (Page 479)

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Accessibility, tags, and reflow
Last updated 1/14/2015
For information on setting the tab order to use document structure, see Set form field navigation.
Add other accessibility features to the PDF
In Acrobat Pro, this stage includes setting the document language, making sure that security settings don’t interfere
with screen readers, creating accessible links, and adding bookmarks. For more information, see
Set the document
language , Prevent security settings from interfering with screen readers , Add accessible links , and About bookmarks .
In Acrobat Standard, this stage includes setting the document language, making sure that security settings don’t
interfere with screen readers, and adding bookmarks. For more information, see
Set the document language , Prevent
security settings from interfering with screen readers , and About bookmarks .
Tag the PDF
Improve the accessibility of PDFs by adding tags in Acrobat. If a PDF doesn’t contain tags, Acrobat attempts to tag it
automatically when users read or reflow it, and the results may be disappointing. With a tagged PDF, the logical
structure tree sends the contents to a screen reader or other assistive software or hardware in an appropriate order.
For best results, tag a document when converting it to PDF from an authoring application. Examples of these
applications include Adobe FrameMaker®, Adobe InDesign®,Microsoft Word, or OpenOffice Writer. If you do not have
access to an authoring application that can generate a tagged PDF, you can tag a PDF any time by using Acrobat.
Tagging during conversion to PDF requires an authoring application that supports tagging in PDF. Tagging during
conversion enables the authoring application to draw from the paragraph styles or other structural information of the
source document to produce a logical structure tree. The logical structure tree reflects an accurate reading order and
appropriate levels of tags. This tagging can more readily interpret the structure of complex layouts, such as embedded
sidebars, closely spaced columns, irregular text alignment, and tables. Tagging during conversion can also properly tag
the links, cross-references, bookmarks, and alternate text (when available) that are in the file.
To tag a PDF in Acrobat, choose Tools > Accessibility > Add Tags To Document. This command works on any untagged
PDF, such as one created with Adobe PDF Printer. Acrobat analyzes the content of the PDF to interpret the individual
page elements, their hierarchical structure, and the intended reading order of each page. Then, it builds a tag tree that
reflects that information. It also creates tags for any links, cross-references, and bookmarks that you added to the
document in Acrobat.
The Add Tags To Document command adequately tags most standard layouts. However, it cannot always correctly
interpret the structure and reading order of complex page elements. These elements include closely spaced columns,
irregular text alignment, nonfillable form fields, and tables that don’t have borders. Tagging these pages by using the
Add Tags To Document command can result in improperly combined elements or out-of-sequence tags. These issues
cause reading order problems in the PDF.
For more information, see Add tags to an existing PDF (Acrobat Pro) .
About watermarks and screen readers
You can add a watermark to a tagged PDF without adding it to the tag tree. Not having a watermark appear in the tag
tree is helpful for people who are using screen readers, because they won’t hear the watermark read as a document
content.
The best way to add a watermark that doesn’t interfere with screen readers is to insert an untagged PDF of the
watermark into a tagged PDF.
Evaluate the PDF and repair tagging problems (Acrobat Pro)
Once you have a tagged PDF, evaluate the document for reading order problems, tagging errors, and accessibility errors,
and then repair them as needed.