Extended Links
Extended links are similar to simple links, except they allow you to link to multiple links instead of just one link. An extended link consists of a set of linking resources and a set of connections between these resources. The linking resources may be local or remote. If all the resources are remote, the link is an out-of-line link. If all the resources are local, the link is an inline link. A local resource is contained in the extended link element and a remote resource is outside of the extended link element.
For more information about extended links, visit the specification Web site, at http://www.w3.org/TR/xlink/.