Cells Spanning Several Rows or Columns

Data and header cells may span several rows or columns. The definition is:

• A data cell that is column-spanned is rendered once, with the row headers as usual and column headers for all its columns, row by row.
• A header cell that is column-spanned is rendered once for each column. If there is a data cell spanned on more then one of these columns, the header is rendered only once for all the columns.
• A data cell that is row-spanned is rendered once for each row.
• A header cell that is row-spanned is rendered once for each row as a row header. If this header cell is also a column header for a data cell, it is treated according to the usual rules and rendered once for the cell.
• If a cell is spanned both from the former row and the column (overlapped), the cell is treated as row-spanned, and the data gathered is that of the previous row.