N OF TRUSTWORTHY DIGITAL REPOSITORIES 
CCSDS 652.0-M-1 
Page 4-12 
September 2011 
external registries.1 Any such registry is a specialized type of repository, which itself must be 
certified/trustworthy. The repository may use these types of standardized, authoritative 
information sources to identify and/or verify the Representation Information components of 
Content Information and PDI. This will reduce the long-term maintenance costs to the 
repository and improve quality control. Sometimes there is bot