No retention/expiration policy to prevent eating up all space for backup location?

Backup & Restore 14 Free
Windows 7 Home Edition x64 SP-1

I found nothing in the manual or program about retention of backups (i.e., when they can be made to expire). Without a retention or expiration policy, the backup location will fill up and end up with insufficient free space for more backups. For example, I might want to keep backups for 6 months and then have the older ones expire and get deleted. Provided that 6 months of backups do not exceed the backup location's capacity, I can continue letting the program perform its scheduled backups. If there is no retention policy to purge old backups and recapture space to ensure further backups will complete successfully, this backup software is a burning fuse that will eventually blow up in the user's face with failed backups because there is no more space in the backup location.