diff --git a/apis/v1beta1/gateway_types.go b/apis/v1beta1/gateway_types.go
index 6eb7cf4eca..2c8548cfac 100644
--- a/apis/v1beta1/gateway_types.go
+++ b/apis/v1beta1/gateway_types.go
@@ -70,7 +70,13 @@ type GatewaySpec struct {
 	// At least one Listener MUST be specified.
 	//
 	// Each listener in a Gateway must have a unique combination of Hostname,
-	// Port, and Protocol.
+	// Port, and Protocol. Below combinations are considered Core and MUST be
+	// supported:
+	//
+	// 1. Port: 80, Protocol: HTTP
+	// 2. Port: 443, Protocol: HTTPS
+	//
+	// Port and protocol combinations not in this list are considered Extended.
 	//
 	// An implementation MAY group Listeners by Port and then collapse each
 	// group of Listeners into a single Listener if the implementation
diff --git a/config/crd/experimental/gateway.networking.k8s.io_gateways.yaml b/config/crd/experimental/gateway.networking.k8s.io_gateways.yaml
index 089f8c5c96..9d9958c4b5 100644
--- a/config/crd/experimental/gateway.networking.k8s.io_gateways.yaml
+++ b/config/crd/experimental/gateway.networking.k8s.io_gateways.yaml
@@ -108,6 +108,9 @@ spec:
                   logical endpoints that are bound on this Gateway's addresses. At
                   least one Listener MUST be specified. \n Each listener in a Gateway
                   must have a unique combination of Hostname, Port, and Protocol.
+                  Below combinations are considered Core and MUST be supported: \n
+                  1. Port: 80, Protocol: HTTP 2. Port: 443, Protocol: HTTPS \n Port
+                  and protocol combinations not in this list are considered Extended.
                   \n An implementation MAY group Listeners by Port and then collapse
                   each group of Listeners into a single Listener if the implementation
                   determines that the Listeners in the group are \"compatible\". An
@@ -811,6 +814,9 @@ spec:
                   logical endpoints that are bound on this Gateway's addresses. At
                   least one Listener MUST be specified. \n Each listener in a Gateway
                   must have a unique combination of Hostname, Port, and Protocol.
+                  Below combinations are considered Core and MUST be supported: \n
+                  1. Port: 80, Protocol: HTTP 2. Port: 443, Protocol: HTTPS \n Port
+                  and protocol combinations not in this list are considered Extended.
                   \n An implementation MAY group Listeners by Port and then collapse
                   each group of Listeners into a single Listener if the implementation
                   determines that the Listeners in the group are \"compatible\". An
diff --git a/config/crd/standard/gateway.networking.k8s.io_gateways.yaml b/config/crd/standard/gateway.networking.k8s.io_gateways.yaml
index 4334414ac7..ad4b556e2f 100644
--- a/config/crd/standard/gateway.networking.k8s.io_gateways.yaml
+++ b/config/crd/standard/gateway.networking.k8s.io_gateways.yaml
@@ -108,6 +108,9 @@ spec:
                   logical endpoints that are bound on this Gateway's addresses. At
                   least one Listener MUST be specified. \n Each listener in a Gateway
                   must have a unique combination of Hostname, Port, and Protocol.
+                  Below combinations are considered Core and MUST be supported: \n
+                  1. Port: 80, Protocol: HTTP 2. Port: 443, Protocol: HTTPS \n Port
+                  and protocol combinations not in this list are considered Extended.
                   \n An implementation MAY group Listeners by Port and then collapse
                   each group of Listeners into a single Listener if the implementation
                   determines that the Listeners in the group are \"compatible\". An
@@ -811,6 +814,9 @@ spec:
                   logical endpoints that are bound on this Gateway's addresses. At
                   least one Listener MUST be specified. \n Each listener in a Gateway
                   must have a unique combination of Hostname, Port, and Protocol.
+                  Below combinations are considered Core and MUST be supported: \n
+                  1. Port: 80, Protocol: HTTP 2. Port: 443, Protocol: HTTPS \n Port
+                  and protocol combinations not in this list are considered Extended.
                   \n An implementation MAY group Listeners by Port and then collapse
                   each group of Listeners into a single Listener if the implementation
                   determines that the Listeners in the group are \"compatible\". An