ing the data must be 
maintained/updated, including the identification of those responsible. This is necessary in 
order to track chain of custody and assert that the repository is providing an authentic copy of 
a particular digital object. The repository must be able to distinguish between versions of 
objects or copies and identical copies. This is necessary in order that a repository can assert 
that it is providing an authentic copy of the correct version of an object. 
5.1.2.1 The repository shall hav