anchor.diff:  |Do not prune any image that is younger than `<duration>` relative to the
   current time. Do not prune any image that is referenced by any other object that
   is younger than `<duration>` relative to the current time. (default `60m`)
  +
  +.^|`--prune-over-size-limit`
  +|Prune each image that exceeds the smallest xref:limits.adoc#image-limits[limit]
  +defined in the same project. This flag cannot be combined with `--keep-tag-revisions`
  +nor `--keep-younger-than`.
   |===
   
   {product-title} uses the following logic to determine which images and layers to
  
positive.code: - the `--keep-tag-revisions` most recent items in
   `*stream.status.tags[].items*`.
  
  * There is no support for pruning from external registries.
  
  * When an image is pruned, all references to the image are removed from all
  
negative.code: 
  == Pruning Images
  
  In order to prune images that are no longer required by the system due to age,
  status, or exceed limits, administrators may run the following command:
  
  ----
  $ oadm prune images [<options>]
  