TVInsert(Parent, After, s) and TVInsertW (Parent, After, s) - creates a node that is a child of Parent, in order following the After node, and sets the string s as text for it;

TVDelete(Node) - deletes the specified node (together with the node, all subordinate nodes are automatically deleted - recursively);

OnTVDelete - an event that is triggered when each node in the tree is deleted. A handler for this event can, for example, release memory, objects, or other resources associated with the item being removed (TVItemData);

Clear - the same as for other visual elements, it works for viewing the tree, deleting all its nodes.