diff --git a/docs/cmd/kn_source_apiserver_create.md b/docs/cmd/kn_source_apiserver_create.md
index 7af099c5d..9c3a0eda8 100644
--- a/docs/cmd/kn_source_apiserver_create.md
+++ b/docs/cmd/kn_source_apiserver_create.md
@@ -26,7 +26,7 @@ kn source apiserver create NAME --resource RESOURCE --sink SINK
       --resource stringArray      Specification for which events to listen, in the format Kind:APIVersion:LabelSelector, e.g. "Event:v1:key=value".
                                   "LabelSelector" is a list of comma separated key value pairs. "LabelSelector" can be omitted, e.g. "Event:v1".
       --service-account string    Name of the service account to use to run this source
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/docs/cmd/kn_source_apiserver_update.md b/docs/cmd/kn_source_apiserver_update.md
index 693e6d23b..023565969 100644
--- a/docs/cmd/kn_source_apiserver_update.md
+++ b/docs/cmd/kn_source_apiserver_update.md
@@ -26,7 +26,7 @@ kn source apiserver update NAME
       --resource stringArray      Specification for which events to listen, in the format Kind:APIVersion:LabelSelector, e.g. "Event:v1:key=value".
                                   "LabelSelector" is a list of comma separated key value pairs. "LabelSelector" can be omitted, e.g. "Event:v1".
       --service-account string    Name of the service account to use to run this source
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/docs/cmd/kn_source_binding_create.md b/docs/cmd/kn_source_binding_create.md
index 3110006d5..d3c5eab75 100644
--- a/docs/cmd/kn_source_binding_create.md
+++ b/docs/cmd/kn_source_binding_create.md
@@ -20,7 +20,7 @@ kn source binding create NAME --subject SUBJECT --sink SINK
       --ce-override stringArray   Cloud Event overrides to apply before sending event to sink. Example: '--ce-override key=value' You may be provide this flag multiple times. To unset, append "-" to the key (e.g. --ce-override key-).
   -h, --help                      help for create
   -n, --namespace string          Specify the namespace to operate in.
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
       --subject string            Subject which emits cloud events. This argument takes format kind:apiVersion:name for named resources or kind:apiVersion:labelKey1=value1,labelKey2=value2 for matching via a label selector
 ```
 
diff --git a/docs/cmd/kn_source_binding_update.md b/docs/cmd/kn_source_binding_update.md
index 18c1562c8..3d8fd4b06 100644
--- a/docs/cmd/kn_source_binding_update.md
+++ b/docs/cmd/kn_source_binding_update.md
@@ -20,7 +20,7 @@ kn source binding update NAME
       --ce-override stringArray   Cloud Event overrides to apply before sending event to sink. Example: '--ce-override key=value' You may be provide this flag multiple times. To unset, append "-" to the key (e.g. --ce-override key-).
   -h, --help                      help for update
   -n, --namespace string          Specify the namespace to operate in.
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
       --subject string            Subject which emits cloud events. This argument takes format kind:apiVersion:name for named resources or kind:apiVersion:labelKey1=value1,labelKey2=value2 for matching via a label selector
 ```
 
diff --git a/docs/cmd/kn_source_container_create.md b/docs/cmd/kn_source_container_create.md
index 7fce6ba84..571bd6349 100644
--- a/docs/cmd/kn_source_container_create.md
+++ b/docs/cmd/kn_source_container_create.md
@@ -30,7 +30,7 @@ kn source container create NAME --image IMAGE --sink SINK
       --pull-secret string       Image pull secret to set. An empty argument ("") clears the pull secret. The referenced secret must exist in the service's namespace.
       --request strings          The resource requirement requests for this Service. For example, 'cpu=100m,memory=256Mi'. You can use this flag multiple times. To unset a resource request, append "-" to the resource name, e.g. '--request cpu-'.
       --service-account string   Service account name to set. An empty argument ("") clears the service account. The referenced service account must exist in the service's namespace.
-  -s, --sink string              Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string              Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
       --user int                 The user ID to run the container (e.g., 1001).
       --volume stringArray       Add a volume from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret: or sc:). Example: --volume myvolume=cm:myconfigmap or --volume myvolume=secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --volume myvolume-.
 ```
diff --git a/docs/cmd/kn_source_container_update.md b/docs/cmd/kn_source_container_update.md
index 82cdb1534..2c32bba02 100644
--- a/docs/cmd/kn_source_container_update.md
+++ b/docs/cmd/kn_source_container_update.md
@@ -30,7 +30,7 @@ kn source container update NAME --image IMAGE
       --pull-secret string       Image pull secret to set. An empty argument ("") clears the pull secret. The referenced secret must exist in the service's namespace.
       --request strings          The resource requirement requests for this Service. For example, 'cpu=100m,memory=256Mi'. You can use this flag multiple times. To unset a resource request, append "-" to the resource name, e.g. '--request cpu-'.
       --service-account string   Service account name to set. An empty argument ("") clears the service account. The referenced service account must exist in the service's namespace.
-  -s, --sink string              Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string              Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
       --user int                 The user ID to run the container (e.g., 1001).
       --volume stringArray       Add a volume from a ConfigMap (prefix cm: or config-map:) or a Secret (prefix secret: or sc:). Example: --volume myvolume=cm:myconfigmap or --volume myvolume=secret:mysecret. You can use this flag multiple times. To unset a ConfigMap/Secret reference, append "-" to the name, e.g. --volume myvolume-.
 ```
diff --git a/docs/cmd/kn_source_ping_create.md b/docs/cmd/kn_source_ping_create.md
index bde2574fe..179177237 100644
--- a/docs/cmd/kn_source_ping_create.md
+++ b/docs/cmd/kn_source_ping_create.md
@@ -22,7 +22,7 @@ kn source ping create NAME --sink SINK
   -h, --help                      help for create
   -n, --namespace string          Specify the namespace to operate in.
       --schedule string           Optional schedule specification in crontab format (e.g. '*/2 * * * *' for every two minutes. By default fire every minute.
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/docs/cmd/kn_source_ping_update.md b/docs/cmd/kn_source_ping_update.md
index 0792aa2de..5336da33b 100644
--- a/docs/cmd/kn_source_ping_update.md
+++ b/docs/cmd/kn_source_ping_update.md
@@ -22,7 +22,7 @@ kn source ping update NAME
   -h, --help                      help for update
   -n, --namespace string          Specify the namespace to operate in.
       --schedule string           Optional schedule specification in crontab format (e.g. '*/2 * * * *' for every two minutes. By default fire every minute.
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/docs/cmd/kn_subscription_create.md b/docs/cmd/kn_subscription_create.md
index aba916c96..ca244a21e 100644
--- a/docs/cmd/kn_subscription_create.md
+++ b/docs/cmd/kn_subscription_create.md
@@ -23,9 +23,9 @@ kn subscription create NAME
       --channel string            Specify the channel to subscribe to. For the default channel, just use the name (e.g. 'mychannel'). A mapped channel type like 'imc' can be used as a prefix (e.g. 'imc:mychannel'). Finally you can specify the full coordinates to the referenced channel with Group:Version:Kind:Name (e.g. 'messaging.knative.dev:v1alpha1:KafkaChannel:mychannel').
   -h, --help                      help for create
   -n, --namespace string          Specify the namespace to operate in.
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
-      --sink-dead-letter string   Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-dead-letter broker:nest' for a broker 'nest', '--sink-dead-letter channel:pipe' for a channel 'pipe', '--sink-dead-letter ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-dead-letter https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-dead-letter ksvc:receiver' or simply '--sink-dead-letter receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
-      --sink-reply string         Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-reply broker:nest' for a broker 'nest', '--sink-reply channel:pipe' for a channel 'pipe', '--sink-reply ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-reply https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-reply ksvc:receiver' or simply '--sink-reply receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
+      --sink-dead-letter string   Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-dead-letter broker:nest' for a broker 'nest', '--sink-dead-letter channel:pipe' for a channel 'pipe', '--sink-dead-letter ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-dead-letter https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-dead-letter ksvc:receiver' or simply '--sink-dead-letter receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
+      --sink-reply string         Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-reply broker:nest' for a broker 'nest', '--sink-reply channel:pipe' for a channel 'pipe', '--sink-reply ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-reply https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-reply ksvc:receiver' or simply '--sink-reply receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/docs/cmd/kn_subscription_update.md b/docs/cmd/kn_subscription_update.md
index ee00435ad..c0512cb4d 100644
--- a/docs/cmd/kn_subscription_update.md
+++ b/docs/cmd/kn_subscription_update.md
@@ -22,9 +22,9 @@ kn subscription update NAME
 ```
   -h, --help                      help for update
   -n, --namespace string          Specify the namespace to operate in.
-  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
-      --sink-dead-letter string   Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-dead-letter broker:nest' for a broker 'nest', '--sink-dead-letter channel:pipe' for a channel 'pipe', '--sink-dead-letter ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-dead-letter https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-dead-letter ksvc:receiver' or simply '--sink-dead-letter receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
-      --sink-reply string         Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-reply broker:nest' for a broker 'nest', '--sink-reply channel:pipe' for a channel 'pipe', '--sink-reply ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-reply https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-reply ksvc:receiver' or simply '--sink-reply receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string               Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
+      --sink-dead-letter string   Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-dead-letter broker:nest' for a broker 'nest', '--sink-dead-letter channel:pipe' for a channel 'pipe', '--sink-dead-letter ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-dead-letter https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-dead-letter ksvc:receiver' or simply '--sink-dead-letter receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
+      --sink-reply string         Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink-reply broker:nest' for a broker 'nest', '--sink-reply channel:pipe' for a channel 'pipe', '--sink-reply ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink-reply https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink-reply ksvc:receiver' or simply '--sink-reply receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/docs/cmd/kn_trigger_create.md b/docs/cmd/kn_trigger_create.md
index 106781c32..d7115ecee 100644
--- a/docs/cmd/kn_trigger_create.md
+++ b/docs/cmd/kn_trigger_create.md
@@ -25,7 +25,7 @@ kn trigger create NAME --sink SINK
   -h, --help               help for create
       --inject-broker      Create new broker with name default through common annotation
   -n, --namespace string   Specify the namespace to operate in.
-  -s, --sink string        Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string        Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/docs/cmd/kn_trigger_update.md b/docs/cmd/kn_trigger_update.md
index b3d0afed8..ed3536e27 100644
--- a/docs/cmd/kn_trigger_update.md
+++ b/docs/cmd/kn_trigger_update.md
@@ -29,7 +29,7 @@ kn trigger update NAME
   -h, --help               help for update
       --inject-broker      Create new broker with name default through common annotation
   -n, --namespace string   Specify the namespace to operate in.
-  -s, --sink string        Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver'. If a prefix is not provided, it is considered as a Knative service.
+  -s, --sink string        Addressable sink for events. You can specify a broker, channel, Knative service or URI. Examples: '--sink broker:nest' for a broker 'nest', '--sink channel:pipe' for a channel 'pipe', '--sink ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', '--sink https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, '--sink ksvc:receiver' or simply '--sink receiver' for a Knative service 'receiver' in the current namespace. If a prefix is not provided, it is considered as a Knative service in the current namespace. If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly.
 ```
 
 ### Options inherited from parent commands
diff --git a/pkg/kn/commands/flags/sink.go b/pkg/kn/commands/flags/sink.go
index 02bf59c6e..063f2328b 100644
--- a/pkg/kn/commands/flags/sink.go
+++ b/pkg/kn/commands/flags/sink.go
@@ -48,8 +48,9 @@ func (i *SinkFlags) AddWithFlagName(cmd *cobra.Command, fname, short string) {
 		"'" + flag + " channel:pipe' for a channel 'pipe', " +
 		"'" + flag + " ksvc:mysvc:mynamespace' for a Knative service 'mysvc' in another namespace 'mynamespace', " +
 		"'" + flag + " https://event.receiver.uri' for an URI with an 'http://' or 'https://' schema, " +
-		"'" + flag + " ksvc:receiver' or simply '" + flag + " receiver' for a Knative service 'receiver'. " +
-		"If a prefix is not provided, it is considered as a Knative service."
+		"'" + flag + " ksvc:receiver' or simply '" + flag + " receiver' for a Knative service 'receiver' in the current namespace. " +
+		"If a prefix is not provided, it is considered as a Knative service in the current namespace. " +
+		"If referring to a Knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly."
 
 	for _, p := range config.GlobalConfig.SinkMappings() {
 		//user configuration might override the default configuration
@@ -107,7 +108,7 @@ func (i *SinkFlags) ResolveSink(ctx context.Context, knclient clientdynamic.KnDy
 		if prefix == "svc" || prefix == "service" {
 			return nil, fmt.Errorf("unsupported sink prefix: '%s', please use prefix 'ksvc' for knative service", prefix)
 		}
-		return nil, fmt.Errorf("unsupported sink prefix: '%s'", prefix)
+		return nil, fmt.Errorf("unsupported sink prefix: '%s', if referring to a knative service in another namespace, 'ksvc:name:namespace' combination must be provided explicitly", prefix)
 	}
 	if ns != "" {
 		namespace = ns