diff --git a/api/envoy/config/accesslog/v3/accesslog.proto b/api/envoy/config/accesslog/v3/accesslog.proto
index 6d494be4aea6d..ca7438c82910b 100644
--- a/api/envoy/config/accesslog/v3/accesslog.proto
+++ b/api/envoy/config/accesslog/v3/accesslog.proto
@@ -29,26 +29,15 @@ message AccessLog {
 
   reserved "config";
 
-  // The name of the access log implementation to instantiate. The name must
-  // match a statically registered access log. Current built-in loggers include:
-  //
-  // #. "envoy.access_loggers.file"
-  // #. "envoy.access_loggers.http_grpc"
-  // #. "envoy.access_loggers.tcp_grpc"
+  // The name of the access log extension to instantiate.
+  // The name must match one of the compiled in loggers.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.access_loggers>` for the default list of available loggers.
   string name = 1;
 
   // Filter which is used to determine if the access log needs to be written.
   AccessLogFilter filter = 2;
 
-  // Custom configuration that depends on the access log being instantiated.
-  // Built-in configurations include:
-  //
-  // #. "envoy.access_loggers.file": :ref:`FileAccessLog
-  //    <envoy_api_msg_extensions.access_loggers.file.v3.FileAccessLog>`
-  // #. "envoy.access_loggers.http_grpc": :ref:`HttpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v3.HttpGrpcAccessLogConfig>`
-  // #. "envoy.access_loggers.tcp_grpc": :ref:`TcpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v3.TcpGrpcAccessLogConfig>`
+  // Custom configuration that must be set according to the access logger extension being instantiated.
   // [#extension-category: envoy.access_loggers]
   oneof config_type {
     google.protobuf.Any typed_config = 4;
diff --git a/api/envoy/config/accesslog/v4alpha/accesslog.proto b/api/envoy/config/accesslog/v4alpha/accesslog.proto
index 62bc8af6913bb..bed654ccbbc98 100644
--- a/api/envoy/config/accesslog/v4alpha/accesslog.proto
+++ b/api/envoy/config/accesslog/v4alpha/accesslog.proto
@@ -29,26 +29,15 @@ message AccessLog {
 
   reserved "config";
 
-  // The name of the access log implementation to instantiate. The name must
-  // match a statically registered access log. Current built-in loggers include:
-  //
-  // #. "envoy.access_loggers.file"
-  // #. "envoy.access_loggers.http_grpc"
-  // #. "envoy.access_loggers.tcp_grpc"
+  // The name of the access log extension to instantiate.
+  // The name must match one of the compiled in loggers.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.access_loggers>` for the default list of available loggers.
   string name = 1;
 
   // Filter which is used to determine if the access log needs to be written.
   AccessLogFilter filter = 2;
 
-  // Custom configuration that depends on the access log being instantiated.
-  // Built-in configurations include:
-  //
-  // #. "envoy.access_loggers.file": :ref:`FileAccessLog
-  //    <envoy_api_msg_extensions.access_loggers.file.v4alpha.FileAccessLog>`
-  // #. "envoy.access_loggers.http_grpc": :ref:`HttpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v4alpha.HttpGrpcAccessLogConfig>`
-  // #. "envoy.access_loggers.tcp_grpc": :ref:`TcpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v4alpha.TcpGrpcAccessLogConfig>`
+  // Custom configuration that must be set according to the access logger extension being instantiated.
   // [#extension-category: envoy.access_loggers]
   oneof config_type {
     google.protobuf.Any typed_config = 4;
diff --git a/api/envoy/config/metrics/v3/stats.proto b/api/envoy/config/metrics/v3/stats.proto
index 307805e65ad8e..4893b5504ac18 100644
--- a/api/envoy/config/metrics/v3/stats.proto
+++ b/api/envoy/config/metrics/v3/stats.proto
@@ -29,13 +29,8 @@ message StatsSink {
   reserved "config";
 
   // The name of the stats sink to instantiate. The name must match a supported
-  // stats sink. The built-in stats sinks are:
-  //
-  // * :ref:`envoy.stat_sinks.statsd <envoy_api_msg_config.metrics.v3.StatsdSink>`
-  // * :ref:`envoy.stat_sinks.dog_statsd <envoy_api_msg_config.metrics.v3.DogStatsdSink>`
-  // * :ref:`envoy.stat_sinks.metrics_service <envoy_api_msg_config.metrics.v3.MetricsServiceConfig>`
-  // * :ref:`envoy.stat_sinks.hystrix <envoy_api_msg_config.metrics.v3.HystrixSink>`
-  //
+  // stats sink.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.stats_sinks>` for the default list of available stats sink.
   // Sinks optionally support tagged/multiple dimensional metrics.
   string name = 1;
 
diff --git a/api/envoy/config/metrics/v4alpha/stats.proto b/api/envoy/config/metrics/v4alpha/stats.proto
index 3a351cdd094c6..e3f10f1da4f61 100644
--- a/api/envoy/config/metrics/v4alpha/stats.proto
+++ b/api/envoy/config/metrics/v4alpha/stats.proto
@@ -29,13 +29,8 @@ message StatsSink {
   reserved "config";
 
   // The name of the stats sink to instantiate. The name must match a supported
-  // stats sink. The built-in stats sinks are:
-  //
-  // * :ref:`envoy.stat_sinks.statsd <envoy_api_msg_config.metrics.v4alpha.StatsdSink>`
-  // * :ref:`envoy.stat_sinks.dog_statsd <envoy_api_msg_config.metrics.v4alpha.DogStatsdSink>`
-  // * :ref:`envoy.stat_sinks.metrics_service <envoy_api_msg_config.metrics.v4alpha.MetricsServiceConfig>`
-  // * :ref:`envoy.stat_sinks.hystrix <envoy_api_msg_config.metrics.v4alpha.HystrixSink>`
-  //
+  // stats sink.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.stats_sinks>` for the default list of available stats sink.
   // Sinks optionally support tagged/multiple dimensional metrics.
   string name = 1;
 
diff --git a/api/envoy/config/overload/v3/overload.proto b/api/envoy/config/overload/v3/overload.proto
index 8817fe0c291b4..4445af6321137 100644
--- a/api/envoy/config/overload/v3/overload.proto
+++ b/api/envoy/config/overload/v3/overload.proto
@@ -32,12 +32,8 @@ message ResourceMonitor {
   reserved "config";
 
   // The name of the resource monitor to instantiate. Must match a registered
-  // resource monitor type. The built-in resource monitors are:
-  //
-  // * :ref:`envoy.resource_monitors.fixed_heap
-  //   <envoy_api_msg_config.resource_monitor.fixed_heap.v2alpha.FixedHeapConfig>`
-  // * :ref:`envoy.resource_monitors.injected_resource
-  //   <envoy_api_msg_config.resource_monitor.injected_resource.v2alpha.InjectedResourceConfig>`
+  // resource monitor type.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.resource_monitors>` for the default list of available resource monitor.
   string name = 1 [(validate.rules).string = {min_len: 1}];
 
   // Configuration for the resource monitor being instantiated.
diff --git a/api/envoy/config/trace/v3/http_tracer.proto b/api/envoy/config/trace/v3/http_tracer.proto
index d0ba3ba6e4fdb..8a3e452db5644 100644
--- a/api/envoy/config/trace/v3/http_tracer.proto
+++ b/api/envoy/config/trace/v3/http_tracer.proto
@@ -43,25 +43,11 @@ message Tracing {
     reserved "config";
 
     // The name of the HTTP trace driver to instantiate. The name must match a
-    // supported HTTP trace driver. Built-in trace drivers:
-    //
-    // - *envoy.tracers.lightstep*
-    // - *envoy.tracers.zipkin*
-    // - *envoy.tracers.dynamic_ot*
-    // - *envoy.tracers.datadog*
-    // - *envoy.tracers.opencensus*
-    // - *envoy.tracers.xray*
+    // supported HTTP trace driver.
+    // See the :ref:`extensions listed in typed_config below <extension_category_envoy.tracers>` for the default list of the HTTP trace driver.
     string name = 1 [(validate.rules).string = {min_len: 1}];
 
-    // Trace driver specific configuration which depends on the driver being instantiated.
-    // See the trace drivers for examples:
-    //
-    // - :ref:`LightstepConfig <envoy_api_msg_config.trace.v3.LightstepConfig>`
-    // - :ref:`ZipkinConfig <envoy_api_msg_config.trace.v3.ZipkinConfig>`
-    // - :ref:`DynamicOtConfig <envoy_api_msg_config.trace.v3.DynamicOtConfig>`
-    // - :ref:`DatadogConfig <envoy_api_msg_config.trace.v3.DatadogConfig>`
-    // - :ref:`OpenCensusConfig <envoy_api_msg_config.trace.v3.OpenCensusConfig>`
-    // - :ref:`AWS X-Ray <envoy_api_msg_config.trace.v3.XRayConfig>`
+    // Trace driver specific configuration which must be set according to the driver being instantiated.
     // [#extension-category: envoy.tracers]
     oneof config_type {
       google.protobuf.Any typed_config = 3;
diff --git a/api/envoy/config/trace/v4alpha/http_tracer.proto b/api/envoy/config/trace/v4alpha/http_tracer.proto
index 4b8c681688425..3e896902c99f2 100644
--- a/api/envoy/config/trace/v4alpha/http_tracer.proto
+++ b/api/envoy/config/trace/v4alpha/http_tracer.proto
@@ -43,25 +43,11 @@ message Tracing {
     reserved "config";
 
     // The name of the HTTP trace driver to instantiate. The name must match a
-    // supported HTTP trace driver. Built-in trace drivers:
-    //
-    // - *envoy.tracers.lightstep*
-    // - *envoy.tracers.zipkin*
-    // - *envoy.tracers.dynamic_ot*
-    // - *envoy.tracers.datadog*
-    // - *envoy.tracers.opencensus*
-    // - *envoy.tracers.xray*
+    // supported HTTP trace driver.
+    // See the :ref:`extensions listed in typed_config below <extension_category_envoy.tracers>` for the default list of the HTTP trace driver.
     string name = 1 [(validate.rules).string = {min_len: 1}];
 
-    // Trace driver specific configuration which depends on the driver being instantiated.
-    // See the trace drivers for examples:
-    //
-    // - :ref:`LightstepConfig <envoy_api_msg_extensions.tracers.lightstep.v4alpha.LightstepConfig>`
-    // - :ref:`ZipkinConfig <envoy_api_msg_extensions.tracers.zipkin.v4alpha.ZipkinConfig>`
-    // - :ref:`DynamicOtConfig <envoy_api_msg_extensions.tracers.dynamic_ot.v4alpha.DynamicOtConfig>`
-    // - :ref:`DatadogConfig <envoy_api_msg_extensions.tracers.datadog.v4alpha.DatadogConfig>`
-    // - :ref:`OpenCensusConfig <envoy_api_msg_extensions.tracers.opencensus.v4alpha.OpenCensusConfig>`
-    // - :ref:`AWS X-Ray <envoy_api_msg_extensions.tracers.xray.v4alpha.XRayConfig>`
+    // Trace driver specific configuration which must be set according to the driver being instantiated.
     // [#extension-category: envoy.tracers]
     oneof config_type {
       google.protobuf.Any typed_config = 3;
diff --git a/generated_api_shadow/envoy/config/accesslog/v3/accesslog.proto b/generated_api_shadow/envoy/config/accesslog/v3/accesslog.proto
index b266ea21b9886..04d6cdd2fd852 100644
--- a/generated_api_shadow/envoy/config/accesslog/v3/accesslog.proto
+++ b/generated_api_shadow/envoy/config/accesslog/v3/accesslog.proto
@@ -26,26 +26,15 @@ message AccessLog {
   option (udpa.annotations.versioning).previous_message_type =
       "envoy.config.filter.accesslog.v2.AccessLog";
 
-  // The name of the access log implementation to instantiate. The name must
-  // match a statically registered access log. Current built-in loggers include:
-  //
-  // #. "envoy.access_loggers.file"
-  // #. "envoy.access_loggers.http_grpc"
-  // #. "envoy.access_loggers.tcp_grpc"
+  // The name of the access log extension to instantiate.
+  // The name must match one of the compiled in loggers.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.access_loggers>` for the default list of available loggers.
   string name = 1;
 
   // Filter which is used to determine if the access log needs to be written.
   AccessLogFilter filter = 2;
 
-  // Custom configuration that depends on the access log being instantiated.
-  // Built-in configurations include:
-  //
-  // #. "envoy.access_loggers.file": :ref:`FileAccessLog
-  //    <envoy_api_msg_extensions.access_loggers.file.v3.FileAccessLog>`
-  // #. "envoy.access_loggers.http_grpc": :ref:`HttpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v3.HttpGrpcAccessLogConfig>`
-  // #. "envoy.access_loggers.tcp_grpc": :ref:`TcpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v3.TcpGrpcAccessLogConfig>`
+  // Custom configuration that must be set according to the access logger extension being instantiated.
   // [#extension-category: envoy.access_loggers]
   oneof config_type {
     google.protobuf.Any typed_config = 4;
diff --git a/generated_api_shadow/envoy/config/accesslog/v4alpha/accesslog.proto b/generated_api_shadow/envoy/config/accesslog/v4alpha/accesslog.proto
index 62bc8af6913bb..bed654ccbbc98 100644
--- a/generated_api_shadow/envoy/config/accesslog/v4alpha/accesslog.proto
+++ b/generated_api_shadow/envoy/config/accesslog/v4alpha/accesslog.proto
@@ -29,26 +29,15 @@ message AccessLog {
 
   reserved "config";
 
-  // The name of the access log implementation to instantiate. The name must
-  // match a statically registered access log. Current built-in loggers include:
-  //
-  // #. "envoy.access_loggers.file"
-  // #. "envoy.access_loggers.http_grpc"
-  // #. "envoy.access_loggers.tcp_grpc"
+  // The name of the access log extension to instantiate.
+  // The name must match one of the compiled in loggers.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.access_loggers>` for the default list of available loggers.
   string name = 1;
 
   // Filter which is used to determine if the access log needs to be written.
   AccessLogFilter filter = 2;
 
-  // Custom configuration that depends on the access log being instantiated.
-  // Built-in configurations include:
-  //
-  // #. "envoy.access_loggers.file": :ref:`FileAccessLog
-  //    <envoy_api_msg_extensions.access_loggers.file.v4alpha.FileAccessLog>`
-  // #. "envoy.access_loggers.http_grpc": :ref:`HttpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v4alpha.HttpGrpcAccessLogConfig>`
-  // #. "envoy.access_loggers.tcp_grpc": :ref:`TcpGrpcAccessLogConfig
-  //    <envoy_api_msg_extensions.access_loggers.grpc.v4alpha.TcpGrpcAccessLogConfig>`
+  // Custom configuration that must be set according to the access logger extension being instantiated.
   // [#extension-category: envoy.access_loggers]
   oneof config_type {
     google.protobuf.Any typed_config = 4;
diff --git a/generated_api_shadow/envoy/config/metrics/v3/stats.proto b/generated_api_shadow/envoy/config/metrics/v3/stats.proto
index 77da528d50269..cc0e6d4ce24dd 100644
--- a/generated_api_shadow/envoy/config/metrics/v3/stats.proto
+++ b/generated_api_shadow/envoy/config/metrics/v3/stats.proto
@@ -26,13 +26,8 @@ message StatsSink {
   option (udpa.annotations.versioning).previous_message_type = "envoy.config.metrics.v2.StatsSink";
 
   // The name of the stats sink to instantiate. The name must match a supported
-  // stats sink. The built-in stats sinks are:
-  //
-  // * :ref:`envoy.stat_sinks.statsd <envoy_api_msg_config.metrics.v3.StatsdSink>`
-  // * :ref:`envoy.stat_sinks.dog_statsd <envoy_api_msg_config.metrics.v3.DogStatsdSink>`
-  // * :ref:`envoy.stat_sinks.metrics_service <envoy_api_msg_config.metrics.v3.MetricsServiceConfig>`
-  // * :ref:`envoy.stat_sinks.hystrix <envoy_api_msg_config.metrics.v3.HystrixSink>`
-  //
+  // stats sink.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.stats_sinks>` for the default list of available stats sink.
   // Sinks optionally support tagged/multiple dimensional metrics.
   string name = 1;
 
diff --git a/generated_api_shadow/envoy/config/metrics/v4alpha/stats.proto b/generated_api_shadow/envoy/config/metrics/v4alpha/stats.proto
index 3a351cdd094c6..e3f10f1da4f61 100644
--- a/generated_api_shadow/envoy/config/metrics/v4alpha/stats.proto
+++ b/generated_api_shadow/envoy/config/metrics/v4alpha/stats.proto
@@ -29,13 +29,8 @@ message StatsSink {
   reserved "config";
 
   // The name of the stats sink to instantiate. The name must match a supported
-  // stats sink. The built-in stats sinks are:
-  //
-  // * :ref:`envoy.stat_sinks.statsd <envoy_api_msg_config.metrics.v4alpha.StatsdSink>`
-  // * :ref:`envoy.stat_sinks.dog_statsd <envoy_api_msg_config.metrics.v4alpha.DogStatsdSink>`
-  // * :ref:`envoy.stat_sinks.metrics_service <envoy_api_msg_config.metrics.v4alpha.MetricsServiceConfig>`
-  // * :ref:`envoy.stat_sinks.hystrix <envoy_api_msg_config.metrics.v4alpha.HystrixSink>`
-  //
+  // stats sink.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.stats_sinks>` for the default list of available stats sink.
   // Sinks optionally support tagged/multiple dimensional metrics.
   string name = 1;
 
diff --git a/generated_api_shadow/envoy/config/overload/v3/overload.proto b/generated_api_shadow/envoy/config/overload/v3/overload.proto
index ae23dd3c69bb1..4b88b27def09e 100644
--- a/generated_api_shadow/envoy/config/overload/v3/overload.proto
+++ b/generated_api_shadow/envoy/config/overload/v3/overload.proto
@@ -29,12 +29,8 @@ message ResourceMonitor {
       "envoy.config.overload.v2alpha.ResourceMonitor";
 
   // The name of the resource monitor to instantiate. Must match a registered
-  // resource monitor type. The built-in resource monitors are:
-  //
-  // * :ref:`envoy.resource_monitors.fixed_heap
-  //   <envoy_api_msg_config.resource_monitor.fixed_heap.v2alpha.FixedHeapConfig>`
-  // * :ref:`envoy.resource_monitors.injected_resource
-  //   <envoy_api_msg_config.resource_monitor.injected_resource.v2alpha.InjectedResourceConfig>`
+  // resource monitor type.
+  // See the :ref:`extensions listed in typed_config below <extension_category_envoy.resource_monitors>` for the default list of available resource monitor.
   string name = 1 [(validate.rules).string = {min_len: 1}];
 
   // Configuration for the resource monitor being instantiated.
diff --git a/generated_api_shadow/envoy/config/trace/v3/http_tracer.proto b/generated_api_shadow/envoy/config/trace/v3/http_tracer.proto
index b679310769a57..80bd8a8ec4a9e 100644
--- a/generated_api_shadow/envoy/config/trace/v3/http_tracer.proto
+++ b/generated_api_shadow/envoy/config/trace/v3/http_tracer.proto
@@ -40,25 +40,11 @@ message Tracing {
         "envoy.config.trace.v2.Tracing.Http";
 
     // The name of the HTTP trace driver to instantiate. The name must match a
-    // supported HTTP trace driver. Built-in trace drivers:
-    //
-    // - *envoy.tracers.lightstep*
-    // - *envoy.tracers.zipkin*
-    // - *envoy.tracers.dynamic_ot*
-    // - *envoy.tracers.datadog*
-    // - *envoy.tracers.opencensus*
-    // - *envoy.tracers.xray*
+    // supported HTTP trace driver.
+    // See the :ref:`extensions listed in typed_config below <extension_category_envoy.tracers>` for the default list of the HTTP trace driver.
     string name = 1 [(validate.rules).string = {min_len: 1}];
 
-    // Trace driver specific configuration which depends on the driver being instantiated.
-    // See the trace drivers for examples:
-    //
-    // - :ref:`LightstepConfig <envoy_api_msg_config.trace.v3.LightstepConfig>`
-    // - :ref:`ZipkinConfig <envoy_api_msg_config.trace.v3.ZipkinConfig>`
-    // - :ref:`DynamicOtConfig <envoy_api_msg_config.trace.v3.DynamicOtConfig>`
-    // - :ref:`DatadogConfig <envoy_api_msg_config.trace.v3.DatadogConfig>`
-    // - :ref:`OpenCensusConfig <envoy_api_msg_config.trace.v3.OpenCensusConfig>`
-    // - :ref:`AWS X-Ray <envoy_api_msg_config.trace.v3.XRayConfig>`
+    // Trace driver specific configuration which must be set according to the driver being instantiated.
     // [#extension-category: envoy.tracers]
     oneof config_type {
       google.protobuf.Any typed_config = 3;
diff --git a/generated_api_shadow/envoy/config/trace/v4alpha/http_tracer.proto b/generated_api_shadow/envoy/config/trace/v4alpha/http_tracer.proto
index 4b8c681688425..3e896902c99f2 100644
--- a/generated_api_shadow/envoy/config/trace/v4alpha/http_tracer.proto
+++ b/generated_api_shadow/envoy/config/trace/v4alpha/http_tracer.proto
@@ -43,25 +43,11 @@ message Tracing {
     reserved "config";
 
     // The name of the HTTP trace driver to instantiate. The name must match a
-    // supported HTTP trace driver. Built-in trace drivers:
-    //
-    // - *envoy.tracers.lightstep*
-    // - *envoy.tracers.zipkin*
-    // - *envoy.tracers.dynamic_ot*
-    // - *envoy.tracers.datadog*
-    // - *envoy.tracers.opencensus*
-    // - *envoy.tracers.xray*
+    // supported HTTP trace driver.
+    // See the :ref:`extensions listed in typed_config below <extension_category_envoy.tracers>` for the default list of the HTTP trace driver.
     string name = 1 [(validate.rules).string = {min_len: 1}];
 
-    // Trace driver specific configuration which depends on the driver being instantiated.
-    // See the trace drivers for examples:
-    //
-    // - :ref:`LightstepConfig <envoy_api_msg_extensions.tracers.lightstep.v4alpha.LightstepConfig>`
-    // - :ref:`ZipkinConfig <envoy_api_msg_extensions.tracers.zipkin.v4alpha.ZipkinConfig>`
-    // - :ref:`DynamicOtConfig <envoy_api_msg_extensions.tracers.dynamic_ot.v4alpha.DynamicOtConfig>`
-    // - :ref:`DatadogConfig <envoy_api_msg_extensions.tracers.datadog.v4alpha.DatadogConfig>`
-    // - :ref:`OpenCensusConfig <envoy_api_msg_extensions.tracers.opencensus.v4alpha.OpenCensusConfig>`
-    // - :ref:`AWS X-Ray <envoy_api_msg_extensions.tracers.xray.v4alpha.XRayConfig>`
+    // Trace driver specific configuration which must be set according to the driver being instantiated.
     // [#extension-category: envoy.tracers]
     oneof config_type {
       google.protobuf.Any typed_config = 3;
diff --git a/tools/protodoc/protodoc.py b/tools/protodoc/protodoc.py
index 7911d33e89426..364f96d5a8751 100755
--- a/tools/protodoc/protodoc.py
+++ b/tools/protodoc/protodoc.py
@@ -76,8 +76,12 @@
 EXTENSION_CATEGORY_TEMPLATE = string.Template("""$anchor
 
 .. tip::
+  EXTENSION_CATEGORY_TRACER
+
   This extension category has the following known extensions:
 
+
+
 $extensions
 
 """)