Why are backups of a previous incarnation marked obsolete without regard to redundancy?

After incomplete recovery and opening a 9i database with resetlogs we ran a full backup which completed successfully. The backup includes a command to delete obsolete backups after it finishes: delete noprompt obsolete device type sbt; RMAN is configured to use REDUNDANCY 2: RMAN configuration parameters are: CONFIGURE RETENTION POLICY TO REDUNDANCY 2; However all the backups from the old incarnation were immediately marked obsolete and deleted without regard to redundancy. 1. Would this behaviour have been different if we had a RECOVERY WINDOW configured instead of REDUNDANCY 2? 2. Is this behaviour the same in later versions of Oracle? --- edit: added output of LIST INCARNATION: RMAN> list incarnation; List of Database Incarnations DB Key Inc Key DB Name DB ID CUR Reset SCN Reset Time ------- ------- -------- ---------------- --- -------------- ---------- 1 1 LIVE 3494832994 NO 1 19-JAN-04 2 2 LIVE 3494832994 NO 11966702870498 01-JAN-14 3 3 LIVE 3494832994 YES 12041003378277 04-JUL-18