Merge pull request #501 from SomtochiAma/weird-ssa-behaviour

Document behaviour when changes are made to fields not stored in git

docs/spec/v1beta2/kustomization.md

@@ -344,6 +344,11 @@ Note that when the `kustomize.toolkit.fluxcd.io/reconcile` annotation is set to
 the controller will no longer apply changes from source, nor will it prune the resource.
 To resume reconciliation, set the annotation to `enabled` or remove it.
 
+Note that due to the way [Kubernetes server-side apply](https://kubernetes.io/docs/reference/using-api/server-side-apply/)
+works, the kustomize-controller can only revert
+changes made to fields it manages. This means that `kubectl edit` changes will only be reverted if
+those fields are present in git.
+
 ## Garbage collection
 
 To enable garbage collection, set `spec.prune` to `true`.