Tom,

VERExists
  Specifies the maximum number of backup versions to retain
  for storage groups/databases that are currently on the Exchange Server.

VERDeleted
  Specifies the maximum number of backup versions to retain
  for storage groups/databases that have been deleted from the
  Exchange Server after being backed up using Tivoli Storage Manager.

RETExtra
  Specifies the number of days to retain a backup version after that
  version becomes inactive. A version becomes inactive when Data
Protection
  for Exchange stores a more recent backup version. The Tivoli Storage
  Manager server deletes inactive versions based on retention time even
  if the number of inactive versions does not exceed the number allowed
  by the VEREXISTS or VERDELETED parameters.

RETOnly
  Specifies the number of days to retain the last backup version of
  storage groups/databases that has been deleted from the Exchange Server.



For more details on the generic definitions, look here:


http://publib.boulder.ibm.com/tividd/td/IBMTivoliStorageManagerforWindows5.2.html


Also, look at the Data Protection for Exchange User's Guide under section:

   "Data Protection for Exchange policy settings"

Thanks,

Del

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> Now that I understand that, how about commenting on
> each of the copy group items in my example, supply a
> definition which is easily understandable, an example
> would suffice. I have read the redbook and I am still
> confused.