The checkpoint command saves
a personal version of an object for your use only. Checkpointing an
object preserves it in a state that is not modifiable, but that you
can delete later when you no longer need it. You must own the object
to perform a checkpoint. To checkpoint
an object, it must be in the working state.
When
you perform a checkpoint, the current version of the object is moved
to the checkpoint state and a new version of the
object is created. All comments specified on the checkpoint command
are applied to the checkpointed object.
The checkpoint command
supports these subcommands: