ted 
were valid.  All documents are subject to revision, and users of this Recommended Practice 
are encouraged to investigate the possibility of applying the most recent editions of the 
documents indicated below.  The CCSDS Secretariat maintains a register of currently valid 
CCSDS documents. 
[1] 
Reference Model for an Open Archival Information System (OAIS).  Recommendation 
for Space Data System Standards, CCSDS 650.0-B-1.  Blue Book.  Issue 1.  
Washington, D.C.: CCSDS, January 2002.  [Also published