In this example, the table object contains the BORDER and RULES attributes. The BORDER attribute has no value and defaults to a single border. The RULES attribute is set to 'cols'. Clicking one of the buttons below changes the table appearance. By clicking the No Borders button, you set RULES to an empty string (""), which should remove all interior borders. In this case, however, the BORDER attribute trumps the RULES attribute, causing all borders to show.

No borders Exterior border All borders
Column borders Groups borders Table row borders

[Right-click and choose View Source from the shortcut menu.]