The <table> element organizes arbitrarily complex relationships of tabular information. This standard table markup allows column or row spanning and table captions or descriptions. A optional title allowed inside the table element provides a caption to describe the table. See simpletable for a simplified table model that can be specialized to represent more regular relationships of data. The <tgroup> element in a table contains column, row, spanning, header and footer specifications, and the body (<tbody>) of the table. The <colspec> element contains a column specification for a table, including assigning a column name and number, cell content alignment, and column width. The table header (<thead>) element precedes the table body (<tbody>) element in a complex table. The <tbody> element contains the rows in a table. The <row> element contains a single row in a table <tgroup>. The <entry> element defines a single cell in a table.