Operation Manual

253
USING ACROBAT 9 STANDARD
Accessibility, tags, and reflow
Last updated 9/30/2011
For more information about PDF accessibility, see www.webaim.org/techniques/acrobat/.
More Help topics
“Recognize text in scanned documents” on page 63
“Set the document language” on page 267
“Prevent security settings from interfering with screen readers” on page 267
“Keys for accessibility” on page 362
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.
Assistive software determines 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. An untagged document
does not have structure information, and Acrobat must infer a structure based on the Reading Order preference
setting. This situation 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.
More Help topics
“Reading PDFs with reflow and accessibility features” on page 255
“Accessibility preferences” on page 255
“Creating accessible PDFs” on page 262
“Making existing PDFs accessible” on page 266
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.