The group tag is used only within the body of a multiple tag to provide additional formatting control between subsets of a multirow data source. The tag takes a column name from the enclosing multiple tag as its only attribute. It repeats a template section as long as the value of the column does not change from row to row.
The group tag alsos sets two additional values in your multirow:
<table> <multiple name="shirts"> <!-- Start a new row if the style changes --> <tr> <td> @shirts.style@ </td> <td> <!-- List colors for the same style in a single cell --> <group column="style"> @shirts.color@ <!-- @shirts.groupnum@ will be the number of the color within the style --> <if @shirts.groupnum_last_p@ false>, </if> <else>, or </if> </group> <!-- End the row if the style is going to change on the next row </td> </tr> </multiple> </table>
Group tags may be nested to perform even more complex formatting.