It defines whether or not the table with have a border. A netscape extension allows this attribute to assume a value. Within the other 3 tags it can have a value of left , right , or center . As an attribute for the TR tag it defines the default alignments for all cells within the row. It can have a value of top , middle , bottom , and baseline .
Baseline requests that all cells in the row are to be vertically aligned to the same baseline.
If present, it means that text defined by these tags cannot be wrapped to fit the width of the cell. This attribute should be used with caution as it can produce very wide cells. It specifies the number of columns in the table the given cell should span. It specifies the number of rows in the table the given cell should span. Spanning in to rows that were never created with TR will result in truncation.