If you enable versioning for a bucket, POST automatically
generates a unique version ID for the object being added. Amazon S3 returns this ID in
the response using the x-amz-version-id response header.
If you suspend versioning for a bucket, Amazon S3 always uses null as the
version ID of the object stored in a bucket.
Amazon S3 is a distributed system. If you enable versioning on a bucket and Amazon S3 receives
multiple write requests for the same object simultaneously, all of the objects will be
stored.
To see sample requests that use versioning, see Sample Request.