the difference between provisioner kubernetes.io/cinder from openstack.org/standalone-cinder
provisioner: kubernetes.io/cinder default driver is described in official documentation.
provisioner: openstack.org/standalone-cinder : a beta feature which was created for use with external Cinder storage.
Here you can find the main discussion about adding additional provisioner toCinder-standalone.
The builtin kubernetes cinder support expects that nodes are deployed on nova instances. In order to use cinder as a standalone storage service I'd like to add an external provisioner. This provisioner creates volumes in cinder and retrieves connection information. It then translates this connection information into a native k8s PV (ie. iscsi or rbd are already implemented).