Use old backups to restore and recover.

 Hi all,

   I configured RETENTION in RMAN is REDUNDANCY = 3, so there are three backups that I can use them to restore and recover database. I want test use old backup (expired) to restore and recover, so I must register them by CATALOG command (I'm using control file as catalog repo). I don't remember some links about use old backups with CATALOG. Any one give me some advise or links that I can reference ? 

   Still question that I need some advise from you: If RETENTION is REDUNDANCY = 3 so archivelog files also will store 3 days. And my disk not enough space to store alots archivelog files. I use command like