220.127.116.11.2 Navigation Node Identifiers
Each navigation node has a navigation node element identifier.
The following restrictions are enforced when using navigation node element identifiers:
Navigation node element identifiers from zero through 999 are reserved and are used only as temporary values for adding new navigation nodes to the navigation structure. This identifier is translated to a valid value greater than 2000 when performing the add operation.
Navigation node element identifiers from 1000 to 2000 can be used only to create navigation nodes from the site definition<2>.