Two documentation issue in this doc:
https://docs.openshift.com/container-platform/4.14/networking/multiple_networks/configuring-multi-network-policy.html
under 'Deny ingress from all pods in all namespaces':
1. This policy cannot be created. The podSelector most be at least an empty dict.
2. Another bug in the same MNP - a policy without policyTypes has no meaning - creating the deny-by-default policy without the policyTypes doesn't have any effect.

Create the following MNP, given as an example in the doc:
apiVersion: k8s.cni.cncf.io/v1beta1
kind: MultiNetworkPolicy
metadata:
  name: deny-by-default
  annotations:
    k8s.v1.cni.cncf.io/policy-for: <network_name>
spec:
  podSelector:
  ingress: []

    1.
    2.
    3.
    

    The MultiNetworkPolicy "deny-by-default" is invalid: spec.podSelector: Required value

This should be the MNP example for this case:
apiVersion: k8s.cni.cncf.io/v1beta1
kind: MultiNetworkPolicy
metadata:
  name: deny-by-default
  annotations:
    k8s.v1.cni.cncf.io/policy-for:<nemespace_name>/<network_name>
spec:
  podSelector: {}
  policyTypes:
  - Ingress
  ingress: []