S3-Compatible API Bucket Versions
The buckets that are in Backblaze B2 Cloud Storage are always versioned by default. Because buckets are versioned, when you delete a file by referencing only the name, the most recent version of that file is deleted and older versions of the file continue to exist in the bucket. Older versions of files can be deleted automatically by using Lifecycle Rules. Lifecycle Rules are currently available only through the Backblaze web UI and the Native API.