Container Registry and S3 Clarification In The Docs

[eiymba]

The EKS installer's bash script modifies this parameter such that it it reads:

containerRegistry:
  ...
  s3storage:
    bucket: <bucket>
  ...

However, the actual readme of the installer suggests this yaml format:

containerRegistry:
  inCluster: false
  external:
    url: <url of registry>
    certificate:
      kind: secret
      name: container-registry-token

So, am I correct it thinking that we can either use S3 as a container registry, or use an external private container registry?