Database Software

I am using the flash recovery area for all my backup files (archive logs, data and control files). I want to use the redundancy retention policy because it is easy to calculate the space requirement. However, I am not clear how the retention policy applies to archive logs.

Say I set the retention policy to be "keeping 3 backups". How does it affect the archive logs? Will archive logs in the flash recovery area be deleted automatically or I need to do it manually. If they are deleted automatically just like dataset files, what is the "retention policy" for them? I do not have a tape device so all archive logs are going to be stay in disk.

Thanks.