21.1.3.3 header

This element specifies a reference, using a unique identifier, to a table header cell that is associated with the current table cell. The identifier representing the reference shall be stored on this element’s val attribute and is used to reference the unique identifier value of a table header cell. The contents of the table header cell designated by a specific unique identifier shall be used as the table header information associated with the table cell that references that specific unique identifier.

If this element is omitted or the value of the header cell identifier cannot be resolved, no header cell shall be associated with the current table cell.

[Example: Consider the following 3 x 3 table with four header cells with values A, B, C, and D and four data cells with values x1, x2, y1, and y2:

A

B

C

x1

x2

D y1 y2 Each of the data cells is associated with two header cells and can be represented in DrawingML as follows:

<a:tbl>
  …
  <a:tr>
    …
    <a:tc >
      …
    </a:tc>
    <a:tc id="HeaderA">
      …
      <a:p>
        <a:r>
          <a:t>A</a:t>
        </a:r>
      </a:p>
    </a:tc>
    …
  </a:tr>
  <a:tr>
    …
    <a:tc id="HeaderC">
      …
      <a:p>
        <a:r>
          <a:t>C</a:t>
        </a:r>
      </a:p>
    </a:tc>
    <a:tc>
      <a:p>
        <a:r>
          <a:t>x1</a:t>
        </a:r>
      </a:p>
      <a:tcPr>
        …
        <a:headers>
          <a:header val="HeaderA" />
          <a:header val="HeaderC" />
        </a:headers>
        …
      </a:tcPr>
    </a:tc>
    …
  </a:tr>
</a:tbl>

The headers element specifies the list of header cells associated with the table cell that has a value of x1. In this example the table cell with the content value of x1 is associated with headers that have an id of HeaderA and HeaderC. end example]

The possible values for this element are defined by the W3C XML Schema string datatype.