remove old incarnation and subsequent backup metadata from rman catalog

Hi dba's

I'm cleaning my rman catalog and found old incarnation backup metadata that I cannot delete.

The rman cleanup script used does the following:

...allocate channels...

configure retention policy to recovery window of 28 days;

configure controlfile autobackup on;

crosscheck backup of database completed before 'sysdate - 28';

crosscheck backup of archivelog all completed before 'sysdate -28';

report obsolete recovery window of 28 days device type 'sbt';

delete force noprompt obsolete recovery window of 28 days device type 'sbt';

delete backup of database completed before 'sysdate-28';

delete backup of archivelog all completed before 'sysdate-28';

backup current controlfile;

...release channels...