RMAN backup question

I have a shell script with the following commands:
 delete noprompt obsolete;
      backup
        check logical  
        database tag='TAG${TAG_FULL}'
           filesperset 1
        current controlfile tag='TAG$(TAG_CTL)';


The TAG_FULL and TAG_CTL shell variables have different values so the resulting files from the database backup and the controlfile backup are going to be different..

I know that when recovering a database I can provide the TAG but what happens if the controlfile and the backupsets of the database have different names such as in this case.

Thank you very much!