The entire page is divided into 12 base columns.
The content column and each sidebar can be anything from 1 up to 11 base columns wide, with the exception when there are no sidebars and the content column is 12 base columns wide.
The layout must always have exactly one content column, but it can have from 0 to 11 sidebars.
The total number of possible layout variations is over 1000.
The current page uses a 4-2-2-2-2 layout. There are four sidebars on the right, each 2 base columns wide and a content column 4 base columns wide, a total of 12.