-`--prune-backups` `[keep-daily=<N>] [,keep-hourly=<N>] [,keep-last=<N>] [,keep-monthly=<N>] [,keep-weekly=<N>] [,keep-yearly=<N>]` ::
+`--keep-all` `<boolean>` ::
+
+Keep all backups. Conflicts with the other options when true.
+
+`--keep-daily` `<N>` ::
+
+Keep backups for the last <N> different days. If there is morethan one backup for a single day, only the latest one is kept.
+
+`--keep-hourly` `<N>` ::
+
+Keep backups for the last <N> different hours. If there is morethan one backup for a single hour, only the latest one is kept.
+
+`--keep-last` `<N>` ::
+
+Keep the last <N> backups.
+
+`--keep-monthly` `<N>` ::
+
+Keep backups for the last <N> different months. If there is morethan one backup for a single month, only the latest one is kept.
+
+`--keep-weekly` `<N>` ::
+
+Keep backups for the last <N> different weeks. If there is morethan one backup for a single week, only the latest one is kept.