BackBlaze B2 - Bucket name restrictions

Bucket Names

When you create a bucket, you get to pick the name for the bucket. The name you pick must be a unique name that has not been used before, by you or by anybody else. In other words - a bucket’s name is globally unique.

Bucket names can consist of upper-case letters, lower-case letters, numbers, and “-”. No other characters are allowed. Even though your bucket can have upper-case letters, bucket names are case insensitive. A bucket name must be at least 6 characters long, and can be at most 50 characters long. These are all allowed bucket names: myBucket, backblaze-images, and bucket-74358734. Bucket names that start with “b2-” are reserved for Backblaze use.

https://www.backblaze.com/b2/docs/buckets.html