What is Recycle Current Volume in Bareos?

Question

Backup

Good afternoon ! Please tell me what the line does in the bareo settings, or rather in the pool settings:
Recycle Current Volume = yes ?
Reading the documentation, it is not entirely clear to me what it is for, apparently if a new volume is needed, then this directive tells the bareos to trim the volume in accordance with the storage periods. What does it mean to trim a volume? How will it look from the side of the volume?