If cells do not specify the column in which they occur, they are placed in the next available column. Calculation of the next available column is complicated by horizontal and vertical spanning. Cells from preceding rows can have a vertical span that causes them to extend into the current row, thus occupying space in the current row. These logically occupied cells are skipped when looking for the next available column. Similarly, if a cell has a horizontal span, it logically occupies the columns that follow it.
Cells can simultaneously span rows and columns.
A cell spans beyond the boundries of the table. A row contains more cells than there are columns in the table. The arrangement of cells in a row forces one or more cells past the last column of the table. The rule below the last row in the table is controlled by the Frame attribute of the enclosing Table or InformalTable and the RowSep of the last row is ignored. If unspecified, this attribute is inherited from enclosing elements.