Oracle 11.2.0.3: How to control age/number of rman backup information in control file

Hello,

the retention policy of rman is set to 3.

If I put down the following statement

rman> list backup of database tag full_backup;

I get the relult of only 2 Backup Sets.

When I have a look at the files system, there are 3 backup pieces of nearly the same size and for the right point of time when full backups are done (sunday´s).

There are Incremental Backups between the full backups every 3 hours starting at 6:00 a.m. until 10 p.m. => 6 incremental backups every day => 30 incremental backus the week (mondays till fridays) => 90 incremental backups for 3 full backups.

Question: Is it possible, that the retention policy works fine but the controlfile does not contain the whole information of the last 3 full backups?