See W3C documentation for the XHTML table model.
The number of rows a cell spans, in other words, a vertical span (The table cell content will be tagged with a <td> or <th> element.)
| Value |
Meaning |
| A counting number |
How many rows this cell will span vertically, e.g., “3”
|
| Default value: 1 (Span 1 row)
|