scope

th - This enumerated attribute defines the cells that the header (defined in the <th>) element relates to. It may have the following values:

• row:  The header relates to all cells of the row it belongs to.
• col: The header relates to all cells of the column it belongs to.
• rowgroup: The header belongs to a rowgroup and relates to all of its cells. These cells can be placed to the right or the left of the header, depending on the value of the dir attribute in the <table> element.
• colgroup: The header belongs to a colgroup and relates to all of its cells.
• auto td -