diff --git a/rosidl_typesupport_introspection_c/resource/srv__type_support.c.em b/rosidl_typesupport_introspection_c/resource/srv__type_support.c.em
index 1977a86e9..ee71830f2 100644
--- a/rosidl_typesupport_introspection_c/resource/srv__type_support.c.em
+++ b/rosidl_typesupport_introspection_c/resource/srv__type_support.c.em
@@ -61,7 +61,7 @@ function_prefix = '__'.join(include_parts) + '__rosidl_typesupport_introspection
 static rosidl_typesupport_introspection_c__ServiceMembers @(function_prefix)__@(service.namespaced_type.name)_service_members = {
   "@('__'.join([package_name] + list(interface_path.parents[0].parts)))",  // service namespace
   "@(service.namespaced_type.name)",  // service name
-  // these two fields are initialized below on the first access
+  // the following fields are initialized below on first access
   NULL,  // request message
   // @(function_prefix)__@(service.request_message.structure.namespaced_type.name)_message_type_support_handle,
   NULL,  // response message
@@ -94,7 +94,7 @@ static rosidl_service_type_support_t @(function_prefix)__@(service.namespaced_ty
   &@(idl_structure_type_to_c_typename(service.namespaced_type))__@(GET_SOURCES_FUNC),
 };
 
-// Forward declaration of request/response type support functions
+// Forward declaration of message type support functions for service members
 const rosidl_message_type_support_t *
 ROSIDL_TYPESUPPORT_INTERFACE__MESSAGE_SYMBOL_NAME(rosidl_typesupport_introspection_c, @(', '.join([package_name] + list(interface_path.parents[0].parts))), @(service.namespaced_type.name + SERVICE_REQUEST_MESSAGE_SUFFIX))();
 
diff --git a/rosidl_typesupport_introspection_cpp/resource/srv__type_support.cpp.em b/rosidl_typesupport_introspection_cpp/resource/srv__type_support.cpp.em
index 227d1915e..0706124c7 100644
--- a/rosidl_typesupport_introspection_cpp/resource/srv__type_support.cpp.em
+++ b/rosidl_typesupport_introspection_cpp/resource/srv__type_support.cpp.em
@@ -68,7 +68,7 @@ namespace rosidl_typesupport_introspection_cpp
 static ::rosidl_typesupport_introspection_cpp::ServiceMembers @(service.namespaced_type.name)_service_members = {
   "@('::'.join([package_name] + list(interface_path.parents[0].parts)))",  // service namespace
   "@(service.namespaced_type.name)",  // service name
-  // these two fields are initialized below on the first access
+  // the following fields are initialized below on first access
   // see get_service_type_support_handle<@('::'.join([package_name] + list(interface_path.parents[0].parts) + [service.namespaced_type.name]))>()
   nullptr,  // request message
   nullptr,  // response message
@@ -111,7 +111,7 @@ get_service_type_support_handle<@('::'.join([package_name] + list(interface_path
   auto service_members = const_cast<::rosidl_typesupport_introspection_cpp::ServiceMembers *>(
     static_cast<const ::rosidl_typesupport_introspection_cpp::ServiceMembers *>(
       service_type_support->data));
-  // make sure that both the request_members_ and the response_members_ are initialized
+  // make sure all of the service_members are initialized
   // if they are not, initialize them
   if (
     service_members->request_members_ == nullptr ||
@@ -134,7 +134,6 @@ get_service_type_support_handle<@('::'.join([package_name] + list(interface_path
         ::@('::'.join([package_name] + list(interface_path.parents[0].parts)))::@(service.response_message.structure.namespaced_type.name)
       >()->data
       );
-
     // initialize the event_members_ with the static function from the external library
     service_members->event_members_ = static_cast<
       const ::rosidl_typesupport_introspection_cpp::MessageMembers *