ion Policies and procedures must be demonstrated to be understandable and 
implementable. 
AUDIT AND CERTIFICATION OF TRUSTWORTHY DIGITAL REPOSITORIES 
CCSDS 652.0-M-1 
Page 3-8 
September 2011 
3.3.3 The repository shall have a documented history of the changes to its operations, 
procedures, software, and hardware. 
Supporting Text 
This is necessary in order to provide an ‘audit trail’ through which stakeholders can identify 
and trace decisions made by the repository. 
Examples of Ways the Repository Ca