diff --git a/docs/conf.yaml b/docs/conf.yaml
deleted file mode 100644
index ab59281..0000000
--- a/docs/conf.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
----
-project_cfg: onap
-project: onap
-
-# Change this to ReleaseBranchName to modify the header
-default-version: latest
-#
diff --git a/docs/sections/architecture.rst b/docs/sections/architecture.rst
index 344b84d..d8b7516 100644
--- a/docs/sections/architecture.rst
+++ b/docs/sections/architecture.rst
@@ -1,6 +1,5 @@
 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
 .. http://creativecommons.org/licenses/by/4.0
-.. _architecture:
 
 
 Architecture
diff --git a/docs/sections/configuration.rst b/docs/sections/configuration.rst
index c12da9e..37e7911 100644
--- a/docs/sections/configuration.rst
+++ b/docs/sections/configuration.rst
@@ -1,11 +1,11 @@
 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
 .. http://creativecommons.org/licenses/by/4.0
-.. _configuration:
+
 
 Configuration
 =============
 
-DACEGEN2 is deployed via helm charts. The configuration are maintained as on values.yaml and can be updated for deployment if necessary.
+DCAEGEN2 is deployed via helm charts. The configuration are maintained as on values.yaml and can be updated for deployment if necessary.
 
 The helm charts for each component can be controlled via a separate override file under its respective component under ``oom/kubernetes/dcaegen2-services/components``
 
diff --git a/docs/sections/installation.rst b/docs/sections/installation.rst
index 38cec81..3a33b15 100644
--- a/docs/sections/installation.rst
+++ b/docs/sections/installation.rst
@@ -1,6 +1,5 @@
 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
 .. http://creativecommons.org/licenses/by/4.0
-.. _installation:
 
 DCAE Deployment (Installation)
 ==============================
@@ -11,4 +10,4 @@
 
    ./installation_oom.rst
    ./installation_MS_ondemand.rst
-   ./installation_test.rst
\ No newline at end of file
+   ./installation_test.rst
diff --git a/docs/sections/services/prh/architecture.rst b/docs/sections/services/prh/architecture.rst
index f0703a7..3231498 100644
--- a/docs/sections/services/prh/architecture.rst
+++ b/docs/sections/services/prh/architecture.rst
@@ -12,4 +12,7 @@
 
 .. image:: ../../images/prhAlgo.png
 
+In London release, a new mode has been introduced which allows a PNF to send the registration event early, before SO registers the PNF in AAI. A timeout can be configured for the time until such an event is considered valid (default set to 1 day). When PRH receives such an event, and does not find the corresponding PNF in AAI, it will retry the check in AAI till either the PNF is found in AAI, or the timeout occurs (whichever is earlier).This does not block the processing of any events received after such a non-correlated event. 
+This mode is not the default mode in which PRH is installed, and has to enabled in the PRH Helm chart. Since it uses a native Kafka consumer and not DMAAP consumer, certain Kafka and Strimzi related configurable parameters are required, as described in the Configuration section.
+
 
diff --git a/docs/sections/services/prh/configuration.rst b/docs/sections/services/prh/configuration.rst
index 5bdc423..560c08c 100644
--- a/docs/sections/services/prh/configuration.rst
+++ b/docs/sections/services/prh/configuration.rst
@@ -1,7 +1,6 @@
 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
 .. http://creativecommons.org/licenses/by/4.0
 
-.. _prh_configuration:
 
 Configuration
 =============
@@ -67,3 +66,30 @@
   }
 
 The configuration is created from PRH helm charts by specifying **applicationConfig**  during ONAP OOM/Kubernetes deployment.
+
+For PRH 1.9.0 version (London) , a new mode has been introduced which allows early PNF registrations. This mode uses a direct Kafka consumer and not the DMAAP consumer. This mode is not the default mode and has to be activated by setting certain environment variables in the Helm chart values.yaml file under **applicationEnv**, as shown below: 
+
+.. code-block:: yaml
+
+
+        - name: kafkaBoostrapServerConfig
+          value: onap-strimzi-kafka-bootstrap:9092
+        - name: groupIdConfig
+          value: OpenDCAE-c12
+        - name: kafkaUsername
+          value: strimzi-kafka-admin
+        - name: kafkaPassword
+          valueFrom:
+            secretKeyRef:
+              key: password
+              name: strimzi-kafka-admin
+        - name: kafkaTopic
+          value: unauthenticated.VES_PNFREG_OUTPUT
+        - name: SPRING_PROFILES_ACTIVE
+          value: autoCommitDisabled
+        - name: JAAS_CONFIG
+          valueFrom:
+            secretKeyRef:
+              key: sasl.jaas.config
+              name: strimzi-kafka-admin
+
diff --git a/docs/sections/services/prh/installation.rst b/docs/sections/services/prh/installation.rst
index eea0d3b..e73fae6 100644
--- a/docs/sections/services/prh/installation.rst
+++ b/docs/sections/services/prh/installation.rst
@@ -1,6 +1,5 @@
 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
 .. http://creativecommons.org/licenses/by/4.0
-.. _prh-installation:
 
 
 Docker Installation
@@ -76,7 +75,7 @@
 
 
 Deployment steps
-~~~~~~~~~~~~~~~~
+================
 
 - Default app config values can be updated in oom/kubernetes/dcaegen2-services/components/dcae-prh/values.yaml.
 
@@ -101,7 +100,7 @@
     helm uninstall dev-dcae-prh
 
 Application Configurations
---------------------------
+==========================
 
 Supported configuration modifiable in HELM charts under **applicationConfig** section.
 
@@ -155,3 +154,31 @@
 The location of the configuration file should be set in ``CBS_CLIENT_CONFIG_PATH`` env, for example:
 
     ``CBS_CLIENT_CONFIG_PATH: /app-config-input/application_config.yaml``
+    
+    
+For PRH 1.9.0 version (London) , a new mode has been introduced which allows early PNF registrations. This mode uses a direct Kafka consumer and not the DMAAP consumer. This mode is not the default mode and has to be activated by setting certain environment variables in the Helm chart values.yaml file under **applicationEnv**, as shown below: 
+
+.. code-block:: yaml
+
+
+        - name: kafkaBoostrapServerConfig
+          value: onap-strimzi-kafka-bootstrap:9092
+        - name: groupIdConfig
+          value: OpenDCAE-c12
+        - name: kafkaUsername
+          value: strimzi-kafka-admin
+        - name: kafkaPassword
+          valueFrom:
+            secretKeyRef:
+              key: password
+              name: strimzi-kafka-admin
+        - name: kafkaTopic
+          value: unauthenticated.VES_PNFREG_OUTPUT
+        - name: SPRING_PROFILES_ACTIVE
+          value: autoCommitDisabled
+        - name: JAAS_CONFIG
+          valueFrom:
+            secretKeyRef:
+              key: sasl.jaas.config
+              name: strimzi-kafka-admin
+
diff --git a/docs/tox.ini b/docs/tox.ini
index 6159677..2efcc2a 100644
--- a/docs/tox.ini
+++ b/docs/tox.ini
@@ -3,7 +3,7 @@
 envlist = docs,docs-linkcheck,docs-spellcheck
 skipsdist = true
 
-[testenv:docs]
+testenv:docs]
 basepython = python3.8
 deps =
     -r{toxinidir}/requirements-docs.txt
@@ -11,8 +11,6 @@
     -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
 commands = 
     sphinx-build -b html -n -d {envtmpdir}/doctrees ./ {toxinidir}/_build/html
-    echo "Generated docs available in {toxinidir}/_build/html"
-#commands = sphinx-build -W -q -b html -n -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/html
 
 whitelist_externals =
     echo
@@ -25,8 +23,8 @@
     -r{toxinidir}/requirements-docs.txt
     -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
     -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
-commands = echo "Link Checking not enforced"    
-#commands = sphinx-build -W -q -b linkcheck -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/linkcheck
+#Link Check not enforced
+commands = sphinx-build -q -b linkcheck -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/linkcheck
  
 [testenv:docs-spellcheck]
 basepython = python3.8
@@ -34,5 +32,5 @@
     -r{toxinidir}/requirements-docs.txt
     -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
     -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
-#commands = echo "Spell Check not enforced"    
-commands = sphinx-build -W -q -b spelling -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/spellcheck
\ No newline at end of file
+#Spell Check not enforced
+commands = sphinx-build -q -b spelling -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/spellcheck