8.2.3 The Base Version

For a given version history, every versionable node that shares that version history (there being at most one such node per workspace) contains a reference to its particular base version within the version history. Among any set of nodes with a common version history, each node may identify a different version as its base version. The base version of a particular node N is the one that will serve as the default immediate predecessor of the next version of N that is created.