(no version information, might be only in CVS)
DomNode->append_sibling -- 
     Adds new sibling to a node
    
Description
object 
DomNode->append_sibling ( object newnode)
     This functions appends a sibling to an existing node.
     The child can be created with e.g.
     domdocument_create_element(),
     domdocument_create_text() etc. or simply by using any
     other node.
    
     Before a new sibling is added it is first duplicated. Therefore the new
     child is a completely new copy which can be modified without changing the
     node which was passed to this function. If the node passed has children
     itself, they will be duplicated as well, which makes it quite easy to
     duplicate large parts of an XML document. The return value is the
     added sibling. If you plan to do further modifications on the added
     sibling you must use the returned node.
    
     This function has been added to provide the behaviour of
     domnode_append_child() as it works till PHP 4.2.
    
     See also domnode_append_before().