This element acts as a container for a group of columns (which are specified
with COL elements), and allows the author to specify default properties for these
columns. This element comes before any of the standard row grouping hierarchies
TBODY and TFOOT),
and only serves to more completely describe organizational characteristics of the
row grouping data that follow (no cell data is contained in COLGROUPs.)
If no COLGROUP elements are present, all columns in the table are assumed to
be part of a single column group. Each COLGROUP grouping can contain zero
or more COL elements.
This attribute specifies a character in the cell content to be used to
align the data in each cell of the column group (the first occurrence
should be used.) The default value for this attribute is the decimal
point character for the current specified language.
[A case-sensitive character within the current browser character set.]
This attribute specifies the spacing offset to the first occurrence of the
alignment character (specified by the CHAR attribute) on each line of cells
in the current column group. The direction of the offset is determined by
the current text direction (set with the DIR attribute or the BDO element.)
This attribute specifies a default for how many columns are in the current
group. It provides a convenient way of grouping columns without the need
to supply COL elements. This attribute should be ignored if the current
COLGROUP contains one or more COL tags.
Specifies the overall width of the column grouping.
[Specified in pixels, a percentage of the table width, or a relative
measure given as a multiple (eg "1*","2*", etc) of other COLGROUP widths.
The special value "0*" should indicate that the minimum width necessary
be used to render the column group and no more.]