  What are ODS-3 and ODS-4? 
 The Question is:
 
 
       We  have heard about and used ODS-1,
   ODS-2 file systems. Now we have ODS-5 which
   is good. My question is: what about ODS-3
   and ODS-4 ? Did they ever exist? Maybe they
   were implemented somewhere in an obscure
   way? Spiralog is one of them?
       Thanks for any info.
 
                      Regards   Csaba
 
 The Answer is:
 
  These are reserved for (and used by) the ISO 9660 and High Sierra
  CD-ROM formats, respectively.
