The HTML <colgroup> Element (or HTML Table Column Group Element) defines a group of columns within a table.

Content categories:
None.

Permitted content:
If the span attribute is present: none, it is an empty element.
If the attribute is not present: zero or more <col> element.

Tag omission:
The start tag may be omitted, if it has a <col> element as its first child and if it is not preceded by a <colgroup> whose end tag has been omitted.

Permitted parent elements:
A <table> element. The <colgroup> must appear after any optional <caption> element but before any <thead>, <th>, <tbody>, <tfoot> and <tr> element.

DOM interface:
HTMLTableColElement
