Nestable lists. Each list item is a container and can contain other lists as well as other elements.
Used with <LI> for list items.
Attributes for UL:
Definition list container.
list item title.
List item definition.
The FOLD attribute for indicating that an element is collapsible (click on a folder icon to toggle shrink/expand a list).
The FOLD attribute specifies that the list is foldable. And the value of that attribute specifies whether or not to fold the intial layout of the list.
It can also take another attribute "LABEL" so that one can tell what the folded list contains.
In this example, the sub list "HTML Stuff" starts out expanded, and the other two sub lists start out collapsed.
And here's the rendering of the markup: