Please note: EVMS Web Technologies recommends trying to avoid the use of tables in PDFs due to their complexity. 

Tagging tables

For best results when tagging tables, Adobe instructs users to use the application that created the document (Microsoft Word, for example) to add tags when the PDF is made. If the source document isn't available, you can add tags in Adobe Acrobat Pro using the Accessibility tool's Autotag Document command. However, you may have to revise the tags if a table does not have clear borders, headings, columns or rows.

Use the Reading Order tool to edit tagged tables. To repair a mistagged table, open the Reading Order table in the Accessibility pane and click on a table tage type label. Then, click the "Table Editor" button in the Reading Order dialog box. You'll notice the table will be shaded in red. Right-click on any cell and select "Table Cell Properties." Here, you can change the type of cell (Header Cell or Data Cell) and select the cell's attributes such as Row Span and Column Span.

A user edits a table using Adobe Acrobat Pro's Reading Order tool.

If the table isn't clearly labeled, use the cursor and click and drag to select the entire table. Then, click Table in the Reading Order dialog box.

You may need to use the Reading Order tool to select and redefine cells as well. Adobe instructs users to split combined cells by creating a tag for each cell. To do this, Adobe instructs users to select a single cell from within a merged cell and click the "Cell" button in the Reading Order dialog box. Repeat this process to split each merged cell.

Learn more about examining and repairing tables and their tags.

Table structure tags

Making tables accessible can be difficult and complex, so it's best to check them manually in the tags tree. Below you will find information about the different table structure tags and how they should appear in the tags tree.

Table rows

Table rows (<TR> tag) in a table must be a child of the following tags: <Table>, <THead>, <TBody> or <TFoot>. Adobe instructs users to make sure that all <TR> tags are a child of a <Table>, <THead>, <TBody> or <TFoot> tag. You can click and drag elements in the tags tree to make these adjustments if need be.

TH and TD

Table Headers (<TH> tags) and Table Data cells (<TD> tags) must be children of a <TR> element. Adobe instructs users to make sure that all <TH> or <TD> tags are placed under a <TR> tag in the tags tree. You can click and drag elements in the tags tree to make these adjustments if need be.

Headers

All tables in a PDF must have a header in order to be accessible. Make sure all tables in your document have table header cells.

Regularity

Accessible tables contain the same number of columns in each row, and the same number of rows in each column.

Summary

Table summaries are not required for accessibility unless the table data cannot be understood without it. However, summaries improve a document's accessibility and we encourage you to add them to tables in your document. To add a table summary, open the Reading Order tool and right-click anywhere in the table. Select "Edit Table Summary" from the options menu. Click "OK" to save the table summary.

A user adds a summary to a table in a PDF using Adobe Acrobat Pro.

According to W3C: "A summary conveys information about the organization of the data in a table and helps users navigate it. For example, if a table has an unusual structure (as in the examples below), information about what content can be found in which row or column can be provided to the user. A summary is usually only needed for complex tables."

Adobe advises users to add a table summary that summarizes the trend that the data shows, makes the data easier to understand or to provide insturctions on how the data should be reviewed.


WCAG requirement: 1.3.1 Info and Relationships