cellpadding Cell Padding (NISO JATS table model)
Amount of space, measured in pixels, between the border of a cell and the contents of a table cell. (This attribute is based on and intended to be converted easily to the XHTML cellpadding attribute.)
Although the Tag Set can enforce only that this attribute contain any text, numbers, or special characters, best practice is to constrain this value to a counting number (positive integer).
OPTIONAL on element: <table>
|Counting number||Thickness, measured in pixels, of the cell padding.|
|Restriction||@cellpadding is an optional attribute; there is no XML default. The typical browser default is “1” pixel.|