The Dogma W4 - details and explanation

Ad 8. The tables

Table elements when used in a web document must be used to define the structure and layout of tabular data, never to define the visual layout of that document.

Former way of formatting text with tables is obsolete, "poisons" document's structure and increases data flow generated by documents. Modern technologies (CSS, XSL) provide extended functionality for document formatting. Formatting a document by placing its parts into the table's cells and nested tables is therefore forbidden. Tables may only be used to display tabular data.

Tables in web documents must be accessible without regard to the browsing environment of the user (except when the browsing environment provides no table support whatsoever), legible...

Tables must not be formatted in such way that they are usable in only particular devices or with particular setup. Any table presentation must not cause two adjacent cells to join. Adjacent cells must be formatted with borders, distinctive background colors or sufficient cell's content spacing. In tables border, cellpadding or cellspacing attributes must not be used with value of 0.

... and preceded by a meaningful title and/or summary.

The summary attribute is mandatory and must contain faithful description of table's structure, purpose and content. A link to a file containing alternative table content description may be present in the table header.