col elementcolgroup element that doesn't have
   a span attribute.spanHTMLTableColElement, same as for
    colgroup elements. This interface defines one member,
    span.
If a col element has a parent and that is a
  colgroup element that itself has a parent that is a
  table element, then the col element
  represents one or more columns in the column group represented by that
  colgroup.
The element may have a span content attribute
  specified, whose value must be a valid non-negative
  integer greater than zero.
The col element and its span attribute take part in the
  table model.
The span IDL
  attribute must reflect the content attribute of the
  same name. The value must be limited to only non-negative
  numbers greater than zero.