1. A robust method for updating a computer-stored hierarchical structure of nodes via a node identification technique, said update retaining properties and parent/child relationships of said hierarchical structure without renumbering existing node ID values associated with said hierarchical structure, said method comprising the steps of: (a) receiving an instruction to insert a new node at an insertion point in said computer-stored hierarchical structure; (b) identifying one of, or a combination of the following: a left node ID value closest to the left of said insertion point or a closest right node ID value closest to the right of said insertion point; (c) calculating a new ID value based upon node ID value(s) identified in (b), said calculated value greater than ID values of nodes to the left of said insertion point and less than ID values of nodes to the right of said insertion point; and (d) updating said computer-stored hierarchical structure by inserting said new node and associating said inserted node with said calculated ID value, wherein order, node ID values, and relationships between parent, child, and siblings in said hierarchical structure of nodes remain unchanged with said insertion of new node.