CC @caseydavenport I think we agreed that an empty list means nothing, right? The pseudo-code in the same proposal, along with the comments on the data types, look clear on this subject.

Yes, I think you're right. That example looks wrong.

I think it's from an older version of the proposal that didn't get updated when the semantics were nailed down.

I believe it should be:

kind: NetworkPolicy
apiVersion: extensions/v1beta1 
metadata:
  name: allow-all
spec:
  podSelector: 
  ingress:
  - {}