1. Select the Reading Order tool.
If you want screen readers to describe graphical elements that illustrate important concepts in a document, you must provide the description using alternate text. Figures aren’t recognized or read by a screen reader unless you add alternate text to the tag properties. If you apply alternate text to text elements, only the description, not the actual text, is read.
1. Select the Reading Order tool.
3. Right-click the figure, and choose Edit Alternate Text from the pop-up menu.
4. In the Edit Alternate Text dialog box, type a new (or edit an existing) description for the figure, and then click OK.
Tables pose a special challenge for screen readers because they present textual or numerical data to be easily referenced visually. Content within table cells can be complex and might contain lists, paragraphs, form fields, or another table.
For best results when tagging tables, use the application that you created the document with to add tags when you create the PDF. If a PDF isn’t tagged, you can add tags by using the Add Tags To Document command. Most tables are properly recognized using this command; however, the command may not recognize a table that lacks clear borders, headings, columns, and rows. Use the Reading Order tool to determine if the table has been properly recognized and to correct recognition problems. To add specialized formatting to tables and table cells, use the Tags panel.
You can use the Table Editor to automatically analyze a table into its components and apply the appropriate tags, but you may still need to check and correct some of these tags manually. By viewing table tags, you can determine whether columns, rows, and cells have been correctly identified. Tables that lack well-defined borders and rules are often tagged incorrectly or contain adjacent page elements. You can correct poorly tagged tables by selecting and redefining them; you can split combined cells by creating a tag for each cell.
To correct complex tagging problems for tables, you often must use the Tags panel.
1. Select the Reading Order tool, and then click Show Tables And Figures.
2. If the table isn’t clearly labeled in the document pane, drag to select the entire table, and then click Table in the dialog box.
3. Click Show Table Cells to make sure that all cells in the table are defined as individual elements.
If one or more cells are merged, use the Reading Order tool to select the area within a single cell, and then click Cell in the dialog box. Repeat for each merged cell.
If cells aren’t highlighted, the table might not use standard table formatting. Re-create the table in the authoring application.
If adding tags to a PDF in Adobe Acrobat results in a tagging structure that is overly complicated or too problematic to fix, you can use the Reading Order tool to remove or replace the current structure. If the document contains mostly text, you can select a page and then remove headings, tables, and other elements to create a cleaner, simpler tagging structure.
Acrobat can retag an already tagged document after you first remove all existing tags from the tree.
1. Open the Tags panel (View > Show/Hide > Navigation Panels > Tags) and select the root (topmost) tag, Tags.
2. In the Tags panel, select Delete Tag from the options menu.
This procedure works best in pages that contain a single column of text. If the page contains multiple columns, each column must be selected and tagged individually.
3. Ctrl-drag around nontext page elements, such as figures and captions, to deselect them until only text is selected on the page. Click Text/Paragraph in the Reading Order dialog box.