diff --git a/cmd/kubeadm/app/apis/kubeadm/v1alpha3/bootstraptokenstring.go b/cmd/kubeadm/app/apis/kubeadm/v1alpha3/bootstraptokenstring.go
index b7efd0e4f3c..99c929813f9 100644
--- a/cmd/kubeadm/app/apis/kubeadm/v1alpha3/bootstraptokenstring.go
+++ b/cmd/kubeadm/app/apis/kubeadm/v1alpha3/bootstraptokenstring.go
@@ -14,10 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// Package v1alpha2 holds the external kubeadm API types of version v1alpha2
-// Note: This file should be kept in sync with the similar one for the internal API
-// TODO: The BootstrapTokenString object should move out to either k8s.io/client-go or k8s.io/api in the future
-// (probably as part of Bootstrap Tokens going GA). It should not be staged under the kubeadm API as it is now.
 package v1alpha3
 
 import (
diff --git a/cmd/kubeadm/app/apis/kubeadm/v1alpha3/doc.go b/cmd/kubeadm/app/apis/kubeadm/v1alpha3/doc.go
index d328aff21d5..5186e1fba14 100644
--- a/cmd/kubeadm/app/apis/kubeadm/v1alpha3/doc.go
+++ b/cmd/kubeadm/app/apis/kubeadm/v1alpha3/doc.go
@@ -14,7 +14,83 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// Package v1alpha2 is the package that contains the libraries that drive the kubeadm binary.
+// Package v1alpha3 is the API (config file) for driving the kubeadm binary.
+// Some of these options are also available as command line flags, but
+// the preferred way to configure kubeadm is to pass a YAML file in with the
+// --config option.
+//
+// A fully populated example of the schema:
+//	apiVersion: kubeadm.k8s.io/v1alpha3
+//	kind: InitConfiguration
+//	etcd:
+//	  # one of local or external
+//	  local:
+//	    image: "k8s.gcr.io/etcd-amd64:3.2.18"
+//	    dataDir: "/var/lib/etcd"
+//	    extraArgs:
+//	      listen-client-urls: "http://10.100.0.1:2379"
+//	    serverCertSANs:
+//	    -  "ec2-10-100-0-1.compute-1.amazonaws.com"
+//	    peerCertSANs:
+//	    - "10.100.0.1"
+//	  external:
+//	    endpoints:
+//	    - "10.100.0.1:2379"
+//	    - "10.100.0.2:2379"
+//	    caFile: "/etcd/kubernetes/pki/etcd/etcd-ca.crt"
+//	    certFile: "/etcd/kubernetes/pki/etcd/etcd.crt"
+//	    certKey: "/etcd/kubernetes/pki/etcd/etcd.key"
+//	networking:
+//	  serviceSubnet: "10.96.0.0/12"
+//	  podSubnet: "10.100.0.1/24"
+//	  dnsDomain: "cluster.local"
+//	kubernetesVersion: "v1.12.0"
+//	ControlPlaneEndpoint: "10.100.0.1:6443"
+//	apiServerExtraArgs:
+//	  authorization-mode: "Node,RBAC"
+//	controlManagerExtraArgs:
+//	  node-cidr-mask-size: 20
+//	schedulerExtraArgs:
+//	  address: "10.100.0.1"
+//	apiServerCertSANs:
+//	- "10.100.1.1"
+//	- "ec2-10-100-0-1.compute-1.amazonaws.com"
+//	certificateDirectory: "/etc/kubernetes/pki"
+//	imageRepository: "k8s.gcr.io"
+//	unifiedControlPlaneImage: "k8s.gcr.io/controlplane:v1.12.0"
+//	auditPolicyConfiguration:
+//	  # https://kubernetes.io/docs/tasks/debug-application-cluster/audit/#audit-policy
+//	  path: "/var/log/audit/audit.json"
+//	  logDir: "/var/log/audit"
+//	  logMaxAge: 7 # in days
+//	featureGates:
+//	  selfhosting: false
+//	clusterName: "example-cluster"
+//	bootstrapTokens:
+//	- token: "9a08jv.c0izixklcxtmnze7"
+//	  description: "kubeadm bootstrap token"
+//	  ttl: "24h"
+//	  usages:
+//	  - "authentication"
+//	  - "signing"
+//	  groups:
+//	  - "system:bootstrappers:kubeadm:default-node-token"
+//	nodeRegistration:
+//	  name: "ec2-10-100-0-1"
+//	  criSocket: "/var/run/dockershim.sock"
+//	  taints:
+//	  - key: "kubeadmNode"
+//	    value: "master"
+//	    effect: "NoSchedule"
+//	  kubeletExtraArgs:
+//	    cgroupDriver: "cgroupfs"
+//	apiEndpoint:
+//	  advertiseAddress: "10.100.0.1"
+//	  bindPort: 6443
+//
+// TODO: The BootstrapTokenString object should move out to either k8s.io/client-go or k8s.io/api in the future
+// (probably as part of Bootstrap Tokens going GA). It should not be staged under the kubeadm API as it is now.
+//
 // +k8s:defaulter-gen=TypeMeta
 // +groupName=kubeadm.k8s.io
 // +k8s:deepcopy-gen=package
diff --git a/cmd/kubeadm/app/apis/kubeadm/v1alpha3/types.go b/cmd/kubeadm/app/apis/kubeadm/v1alpha3/types.go
index c5f9982d25a..faa08cfb976 100644
--- a/cmd/kubeadm/app/apis/kubeadm/v1alpha3/types.go
+++ b/cmd/kubeadm/app/apis/kubeadm/v1alpha3/types.go
@@ -234,9 +234,7 @@ type LocalEtcd struct {
 
 // ExternalEtcd describes an external etcd cluster
 type ExternalEtcd struct {
-
-	// Endpoints of etcd members. Useful for using external etcd.
-	// If not provided, kubeadm will run etcd in a static pod.
+	// Endpoints of etcd members. Required for ExternalEtcd.
 	Endpoints []string `json:"endpoints"`
 	// CAFile is an SSL Certificate Authority file used to secure etcd communication.
 	CAFile string `json:"caFile"`