Add default storageclass annotation (#27419)

* Add default storageclass annotation

* Add review suggestions

Co-authored-by: Rey Lejano <[email protected]>

Co-authored-by: Rey Lejano <[email protected]>

Author: rikatz

content/en/docs/reference/labels-annotations-taints.md

@@ -224,6 +224,14 @@ When a single IngressClass resource has this annotation set to `"true"`, new Ing
 
 {{< note >}} Starting in v1.18, this annotation is deprecated in favor of `spec.ingressClassName`. {{< /note >}}
 
+## storageclass.kubernetes.io/is-default-class
+
+Example: `storageclass.kubernetes.io/is-default-class=true`
+
+Used on: StorageClass
+
+When a single StorageClass resource has this annotation set to `"true"`, new Physical Volume Claim resource without a class specified will be assigned this default class.
+
 ## alpha.kubernetes.io/provided-node-ip
 
 Example: `alpha.kubernetes.io/provided-node-ip: "10.0.0.1"`