Use only basic table tags
Part of the problem with layout tables is that nonvisual users cannot ignore them. Since tables are a structural element, they must be accounted for when they appear on the page. Table markup is important when working with tabular information, particularly for nonvisual users. The tags and attributes associated with the table element allow nonvisual users to understand and navigate information presented in tabular format. With one element (
TABLE) used for two quite distinct purposes (layout and data), and with no markup to distinguish between the two, nonvisual users have little choice but to pay attention to each table. Since layout tables are so prevalent, some screen reader software manufacturers have programmed their software to differentiate between layout tables and data tables. For example, software may decide a table is for layout if it has only one row, or is without row or column headings. When software identifies a layout table, it can ignore the table attributes and read the contents of the table in the order it appears in the code.
Layout tables should only make use of the most basic row and cell markup (
TD). Headings, captions, summary—all the elements that describe a data table—are meaningless in the layout context. If these elements are present, software that reads Web pages may try to make logical sense of the layout table by, for example, associating cells with headings.