Merge master into dev-1.21 to keep in sync, plus latest API reference

This sync merge includes API reference updates.

content/en/docs/concepts/architecture/nodes.md

@@ -67,6 +67,16 @@ delete the Node object to stop that health checking.
 The name of a Node object must be a valid
 [DNS subdomain name](/docs/concepts/overview/working-with-objects/names#dns-subdomain-names).
 
+### Node name uniqueness
+
+The [name](/docs/concepts/overview/working-with-objects/names#names) identifies a Node. Two Nodes
+cannot have the same name at the same time. Kubernetes also assumes that a resource with the same
+name is the same object. In case of a Node, it is implicitly assumed that an instance using the
+same name will have the same state (e.g. network settings, root disk contents). This may lead to
+inconsistencies if an instance was modified without changing its name. If the Node needs to be
+replaced or updated significantly, the existing Node object needs to be removed from API server
+first and re-added after the update.
+
 ### Self-registration of Nodes
 
 When the kubelet flag `--register-node` is true (the default), the kubelet will attempt to
@@ -381,4 +391,3 @@ reserved for terminating [critical pods](/docs/tasks/administer-cluster/guarante
 * Read the [Node](https://git.k8s.io/community/contributors/design-proposals/architecture/architecture.md#the-kubernetes-node)
   section of the architecture design document.
 * Read about [taints and tolerations](/docs/concepts/scheduling-eviction/taint-and-toleration/).
-