233
ADOBE ACROBAT 8 STANDARD
User Guide
See also
“Recognize text in scanned documents” on page 64
“Set the document language” on page 245
“Prevent security settings from interfering with screen readers” on page 245
About tags, accessibility, reading order, and reflow
PDF tags are similar in many ways to XML tags. PDF tags indicate document structure: which text is a heading,
which content makes up a section, which text is a bookmark, and so on. A logical structure tree of tags represents
the organizational structure of the document. Thus tags can indicate the precise reading order and improve
navigation—particularly for longer, more complex documents—without changing the appearance of the PDF.
For people who are unable to see or interpret the visual appearance of a document, assistive software can determine
how to present and interpret the content of the document by using the logical structure tree. Most assistive software
depends on document structure tags to determine the appropriate reading order of text and to convey the meaning
of images and other content in an alternate format, such as sound. In an untagged document, there is no such
structure information, and Acrobat must infer a structure based on the Reading Order preference setting, which
often results in page items being read in the wrong order or not at all.
Reflowing a document for viewing on the small screen of a mobile device relies on these same document structure tags.
Often, Acrobat tags PDFs when you create them. To determine whether a PDF contains tags, choose File >
Properties, and look at the Tagged PDF value in the Advanced pane of the Description tab.
See also
“Reading PDFs with reflow and accessibility features” on page 235
“Creating accessible PDFs” on page 241
“Making existing PDFs accessible” on page 245
Checking the accessibility of PDFs
About accessibility checkers
Of course, the best way to test the accessibility of a document is to attempt to use the document with the tools that
your readers will use. However, even if you don’t have a screen reader or braille printer, you can still use any of several
methods provided by Acrobat for checking the accessibility of a PDF.
•
Use Quick Check to check for document structure tags, searchable text, and appropriate security settings for
accessibility. This method is often the best way to check for accessibility before attempting to use a PDF.
•
Use Reflow view to quickly check reading order.
•
Use Read Out Loud to experience the document as it will be experienced by readers who use this text-to-speech
conversion tool.
•
Save the document as accessible text and then read the saved text file in a word-processing application to
experience the document as it will be experienced by readers who use a braille printer.