See W3C documentation for the XHTML table model or Mathematical Markup Language (MathML) 2.0 Tag Set, dependent upon model involved.
In an XHTML table, this attribute specifies the desired width of the entire table and is intended for visual user agents. When the value is a percentage value, the value is relative to the user agent’s available horizontal space. In the absence of any width specification, table width is determined by the user agent. The width value can be either an integer number of pixels or a percentage of the width of the display window.
| Value | Meaning |
|---|---|
| Number | For usage with XHTML table model elements, the number that specifies the width of the table. For usage with <mml:math>, see MathML documentation. |
| Restriction: This attribute may be specified if the element is used. | |