ARO networking pre-req : minimum CIDR doc is confusing

ARO Doc states:

- _Pod CIDRs should be minimum **/18** in size. (The pod network is nonroutable IPs, and is only used inside the OpenShift SDN.)_
- _Each node is allocated **/23** subnet (512 IPs) for its pods. **This value can't be changed**._

so if the Pod CIDR is /23, it can not be /18, the way it is written is a bit confusing

Also why does it refer to OpenShift SDN whiich is supposed to be deprecated in favor of [OVN-Kubernetes network plugin](https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html/ovn-kubernetes_network_plugin/about-ovn-kubernetes) ?

[https://learn.microsoft.com/en-us/azure/openshift/concepts-networking#networking-basics-in-openshift](https://learn.microsoft.com/en-us/azure/openshift/concepts-networking#networking-basics-in-openshift
) still refers to _OpenShift Software Defined Networking (SDN) is used to configure an overlay network using Open vSwitch (OVS)_
whereas [https://learn.microsoft.com/en-us/azure/openshift/concepts-ovn-kubernetes#ovn-kubernetes-features](https://learn.microsoft.com/en-us/azure/openshift/concepts-ovn-kubernetes#ovn-kubernetes-features) states that _Since version 4.11, OVN-Kubernetes has been the CNI for all new Azure Red Hat OpenShift clusters. For clusters created before then, migrating from the previous SDN standard to OVN is recommended. SDN has been deprecated since version 4.14 and will no longer be supported after version 4.16. You must migrate to OVN-Kubernetes prior to updating to 4.17._

Doc ref:
- [https://learn.microsoft.com/en-us/azure/openshift/concepts-networking#networking-for-azure-red-hat-openshift](https://learn.microsoft.com/en-us/azure/openshift/concepts-networking#networking-for-azure-red-hat-openshift)
- [https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html/networking_overview/cidr-range-definitions](https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html/networking_overview/cidr-range-definitions)