small updates

docs/modules/ROOT/pages/reference/arch-control-plane.adoc

@@ -68,6 +68,10 @@ spec:
 
 This configuration can be overwritten per organization namespace, for example to give access to "beta" services or additional zones.
 
+== Crossplane ProviderConfig
+
+TODO: Describe the use of `ProviderConfig` with labels to be selected automatically, e.g. for the Namespace reconciler (multiple CSPCPs at one CSP).
+
 == Service Catalog
 
 The service catalog is composed of the available https://docs.crossplane.io/v1.18/concepts/compositions/[Crossplane Compositions^].
@@ -114,7 +118,7 @@ The catalog reconciler:
 
 * Queries the <<Origin Metadata, origin configuration>> for catalog configuration
 * If `mandatoryExternalServiceRequest` is `true`, gets the `ExternalServiceRequest` objects in the namespace
-* Gets the matching `Composition`s, according to the label selector and `ExternalServiceRequest`s
+* Gets the matching `Compositions`, according to the label selector and `ExternalServiceRequests`
 * For each matching composition, a `Catalog` object is created in the namespace with all the needed information.
 
 The `ExternalServiceRequest` defines which service is available.
@@ -179,6 +183,7 @@ sequenceDiagram
 
 * TODO: How are credentials synchronized from the CSPCP to the CCP for the end-user to see?
 * TODO: How to give end-user access to backup listing?
+* TODO: Describe where the `spec.providerConfigRef.name` comes from
 
 === Validation
 
@@ -192,9 +197,12 @@ We need the organization namespace on the CSPCP to place Claims into it.
 For that we use `provider-kubernetes` as we already have the configuration available.
 
 An XRD `RemoteNamespace` is provided which handles `Namespaces` on remote clusters.
+The Composition then uses `provider-kubernetes` with the `spec.providerConfigRef.name` set to the CSPCP where the Namespace needs to be created at.
+
 A controller watches Namespaces on the CCP which managed `RemoteNamespace` objects in the Organization Namespaces and configures them according to the Origin of the Organization.
 
-TODO: Expand this concept with examples.
+* TODO: Expand this concept with examples.
+* TODO: Support multiple CSPCPs on the same CSP
 
 == Service Deprovisioning