Adobe Acrobat 7 Professional - Manual (Page 376)

Checking a document's reading order
When you use the Add Tags To Document command on a PDF document, Adobe Acrobat
analyzes the page structure to determine the role and order of page content. Once the page
has been analyzed, a logical structure tree is added that determines the order in which
page content is reflowed and read by screen readers or the Read Out Loud feature.
Structure recognition is very difficult in complex page layouts that contain elements such
as closely placed columns, irregular text alignment, noninteractive forms, or tables
without borders. Tagging these pages can result in improperly combined elements or out-
of-sequence tags that cause reflow and reading-order problems in a PDF document.
You can quickly check the reading order of tagged PDF documents by using the TouchUp
Reading Order tool. You can also use this tool to add alternate text to images and correct
many types of tagging problems that are outlined in the confidence log report that Acrobat
generates when you add tags to a PDF document. (See
Viewing the results of adding tags
and Correcting tags .) If you need a greater level of editing control over tags on a
substructure level or if you work with PDF documents that require detailed tagging of
tables, use the Tags tab. (See
Using the Tags tab .)
Related Subtopics:
Using the TouchUp Reading Order tool
TouchUp Reading Order options
Identifying and correcting reading-order problems