diff --git a/appengine-java8/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java b/appengine-java8/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java
index 50d97b4a3dd..907c83fe607 100644
--- a/appengine-java8/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java
+++ b/appengine-java8/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java
@@ -22,7 +22,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START simple_logging_example]
+// [START gae_java8_logging_example]
 // With @WebServlet annotation the webapp/WEB-INF/web.xml is no longer required.
 @WebServlet(
     name = "RequestLogging",
@@ -44,4 +44,4 @@ public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOExc
     // [END_EXCLUDE]
   }
 }
-// [END simple_logging_example]
+// [END gae_java8_logging_example]
diff --git a/appengine-java8/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java b/appengine-java8/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java
index bf575133b85..c0fec78ba48 100644
--- a/appengine-java8/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java
+++ b/appengine-java8/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java
@@ -21,7 +21,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START simple_request_example]
+// [START gae_java8_request_example]
 // With @WebServlet annotation the webapp/WEB-INF/web.xml is no longer required.
 @WebServlet(name = "requests", description = "Requests: Trivial request", urlPatterns = "/requests")
 public class RequestsServlet extends HttpServlet {
@@ -32,4 +32,4 @@ public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOExc
     resp.getWriter().println("Hello, world");
   }
 }
-// [END simple_request_example]
+// [END gae_java8_request_example]
diff --git a/appengine/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java b/appengine/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java
index 38916aa67da..2115d799d4b 100644
--- a/appengine/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java
+++ b/appengine/requests/src/main/java/com/example/appengine/requests/LoggingServlet.java
@@ -21,7 +21,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START simple_logging_example]
+// [START gae_java_logging_example]
 public class LoggingServlet extends HttpServlet {
   private static final Logger log = Logger.getLogger(LoggingServlet.class.getName());
 
@@ -36,6 +36,5 @@ public void doGet(HttpServletRequest req, HttpServletResponse resp)
     resp.getWriter().println("Check logs for results");
     // [END_EXCLUDE]
   }
-} 
-// [END simple_logging_example]
-
+}
+// [END gae_java_logging_example]
diff --git a/appengine/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java b/appengine/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java
index 8dff3498311..638af2167f6 100644
--- a/appengine/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java
+++ b/appengine/requests/src/main/java/com/example/appengine/requests/RequestsServlet.java
@@ -20,7 +20,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START simple_request_example]
+// [START gae_java_request_example]
 public class RequestsServlet extends HttpServlet {
   @Override
   public void doGet(HttpServletRequest req, HttpServletResponse resp)
@@ -29,5 +29,4 @@ public void doGet(HttpServletRequest req, HttpServletResponse resp)
     resp.getWriter().println("Hello, world");
   }
 }
-// [END simple_request_example]
-
+// [END gae_java_request_example]
diff --git a/flexible/analytics/src/main/appengine/app.yaml b/flexible/analytics/src/main/appengine/app.yaml
index 3273b02a0e8..be578da0625 100644
--- a/flexible/analytics/src/main/appengine/app.yaml
+++ b/flexible/analytics/src/main/appengine/app.yaml
@@ -5,7 +5,7 @@ handlers:
 - url: /.*
   script: this field is required, but ignored
 
-# [START env_variables]
+# [START gae_flex_analytics_env_variables]
 env_variables:
   GA_TRACKING_ID: YOUR-GA-TRACKING-ID
-# [END env_variables]
+# [END gae_flex_analytics_env_variables]
diff --git a/flexible/analytics/src/main/java/com/example/analytics/AnalyticsServlet.java b/flexible/analytics/src/main/java/com/example/analytics/AnalyticsServlet.java
index 6ae1033c9d6..198aa35e02c 100644
--- a/flexible/analytics/src/main/java/com/example/analytics/AnalyticsServlet.java
+++ b/flexible/analytics/src/main/java/com/example/analytics/AnalyticsServlet.java
@@ -29,7 +29,7 @@
 import org.apache.http.client.utils.URIBuilder;
 import org.apache.http.impl.client.HttpClientBuilder;
 
-// [START example]
+// [START gae_flex_analytics_track_event]
 @SuppressWarnings("serial")
 @WebServlet(name = "analytics", value = "")
 public class AnalyticsServlet extends HttpServlet {
@@ -63,4 +63,4 @@ public void doGet(HttpServletRequest req, HttpServletResponse resp)
     resp.getWriter().println("Event tracked.");
   }
 }
-// [END example]
+// [END gae_flex_analytics_track_event]
diff --git a/flexible/cloudsql/pom.xml b/flexible/cloudsql/pom.xml
index 12ba5547e23..7fa6f1560ce 100644
--- a/flexible/cloudsql/pom.xml
+++ b/flexible/cloudsql/pom.xml
@@ -30,7 +30,7 @@
     <version>1.0.9</version>
   </parent>
 
-<!-- [START properties] -->
+<!-- [START gae_flex_mysql_properties] -->
   <properties>
 <!--
     INSTANCE_CONNECTION_NAME from Cloud Console > SQL > Instance Details > Properties
@@ -50,7 +50,7 @@
 <!-- [END_EXCLUDE] -->
     <sqlURL>jdbc:mysql://google/${database}?cloudSqlInstance=${INSTANCE_CONNECTION_NAME}&amp;socketFactory=com.google.cloud.sql.mysql.SocketFactory&amp;user=${user}&amp;password=${password}&amp;useSSL=false</sqlURL>
   </properties>
-<!-- [END properties] -->
+<!-- [END gae_flex_mysql_properties] -->
 
   <dependencies>
     <dependency>
@@ -75,7 +75,7 @@
       <type>jar</type>
       <scope>provided</scope>
     </dependency>
-    <!-- [START dependencies] -->
+    <!-- [START gae_flex_mysql_dependencies] -->
     <dependency>                        <!-- http://dev.mysql.com/doc/connector-j/en/ -->
       <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
@@ -86,17 +86,17 @@
       <artifactId>mysql-socket-factory-connector-j-6</artifactId>
       <version>1.0.10</version>
     </dependency>
-    <!-- [END dependencies] -->
+    <!-- [END gae_flex_mysql_dependencies] -->
   </dependencies>
   <build>
-    <!-- [START resources] -->
+    <!-- [START gae_flex_mysql_resources] -->
     <resources>
       <resource>
         <directory>src/main/resources</directory>
         <filtering>true</filtering>
       </resource>
     </resources>
-    <!-- [END resources] -->
+    <!-- [END gae_flex_mysql_resources] -->
     <!-- for hot reload of the web application -->
     <outputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes</outputDirectory>
     <plugins>
diff --git a/flexible/cloudsql/src/main/java/com/example/cloudsql/CloudSqlServlet.java b/flexible/cloudsql/src/main/java/com/example/cloudsql/CloudSqlServlet.java
index 80826a40dea..79d678b4ccc 100644
--- a/flexible/cloudsql/src/main/java/com/example/cloudsql/CloudSqlServlet.java
+++ b/flexible/cloudsql/src/main/java/com/example/cloudsql/CloudSqlServlet.java
@@ -39,7 +39,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START example]
+// [START gae_flex_mysql_app]
 @SuppressWarnings("serial")
 @WebServlet(name = "cloudsql", value = "")
 public class CloudSqlServlet extends HttpServlet {
@@ -126,4 +126,4 @@ public void init() throws ServletException {
     }
   }
 }
-// [END example]
+// [END gae_flex_mysql_app]
diff --git a/flexible/cloudstorage/src/main/appengine/app.yaml b/flexible/cloudstorage/src/main/appengine/app.yaml
index da52dfa3ff2..c1b2c4799e2 100644
--- a/flexible/cloudstorage/src/main/appengine/app.yaml
+++ b/flexible/cloudstorage/src/main/appengine/app.yaml
@@ -5,7 +5,5 @@ handlers:
 - url: /.*
   script: this field is required, but ignored
 
-# [START env_variables]
 env_variables:
   BUCKET_NAME: YOUR-BUCKET-NAME
-# [END env_variables]
diff --git a/flexible/cloudstorage/src/main/java/com/example/cloudstorage/UploadServlet.java b/flexible/cloudstorage/src/main/java/com/example/cloudstorage/UploadServlet.java
index 22ae9db90a2..f296e3e8f2b 100644
--- a/flexible/cloudstorage/src/main/java/com/example/cloudstorage/UploadServlet.java
+++ b/flexible/cloudstorage/src/main/java/com/example/cloudstorage/UploadServlet.java
@@ -34,7 +34,7 @@
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.Part;
 
-// [START example]
+// [START gae_flex_storage_app]
 @SuppressWarnings("serial")
 @WebServlet(name = "upload", value = "/upload")
 @MultipartConfig()
@@ -67,4 +67,4 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOEx
     resp.getWriter().print(blob.getMediaLink());
   }
 }
-// [END example]
+// [END gae_flex_storage_app]
diff --git a/flexible/datastore/pom.xml b/flexible/datastore/pom.xml
index 2cb08456982..ed2653c3ed8 100644
--- a/flexible/datastore/pom.xml
+++ b/flexible/datastore/pom.xml
@@ -45,13 +45,13 @@
       <type>jar</type>
       <scope>provided</scope>
     </dependency>
-    <!-- [START dependencies] -->
+    <!-- [START gae_flex_datastore_config] -->
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-datastore</artifactId>
       <version>1.38.0</version>
     </dependency>
-    <!-- [END dependencies] -->
+    <!-- [END gae_flex_datastore_config] -->
   </dependencies>
   <build>
     <!-- for hot reload of the web application -->
diff --git a/flexible/datastore/src/main/java/com/example/datastore/DatastoreServlet.java b/flexible/datastore/src/main/java/com/example/datastore/DatastoreServlet.java
index 341c0763a7d..3742964ef34 100644
--- a/flexible/datastore/src/main/java/com/example/datastore/DatastoreServlet.java
+++ b/flexible/datastore/src/main/java/com/example/datastore/DatastoreServlet.java
@@ -39,7 +39,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START example]
+// [START gae_flex_datastore_app]
 @SuppressWarnings("serial")
 @WebServlet(name = "datastore", value = "")
 public class DatastoreServlet extends HttpServlet {
@@ -82,4 +82,4 @@ public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOExc
     }
   }
 }
-// [END example]
+// [END gae_flex_datastore_app]
diff --git a/flexible/mailgun/pom.xml b/flexible/mailgun/pom.xml
index b027b8a65b3..f6d79b603ff 100644
--- a/flexible/mailgun/pom.xml
+++ b/flexible/mailgun/pom.xml
@@ -48,7 +48,7 @@
       <type>jar</type>
       <scope>provided</scope>
     </dependency>
-    <!-- [START dependencies] -->
+    <!-- [START gae_flex_mailgun_dependencies] -->
     <dependency>
       <groupId>com.sun.jersey</groupId>
       <artifactId>jersey-core</artifactId>
@@ -64,7 +64,7 @@
       <artifactId>jersey-multipart</artifactId>
       <version>1.19.4</version>
     </dependency>
-    <!-- [END dependencies] -->
+    <!-- [END gae_flex_mailgun_dependencies] -->
   </dependencies>
 
   <build>
diff --git a/flexible/mailgun/src/main/java/com/example/mailgun/MailgunServlet.java b/flexible/mailgun/src/main/java/com/example/mailgun/MailgunServlet.java
index 8d990fb2289..fc1cb3e4103 100644
--- a/flexible/mailgun/src/main/java/com/example/mailgun/MailgunServlet.java
+++ b/flexible/mailgun/src/main/java/com/example/mailgun/MailgunServlet.java
@@ -33,7 +33,6 @@
 import javax.servlet.http.HttpServletResponse;
 import javax.ws.rs.core.MediaType;
 
-// [START example]
 @SuppressWarnings("serial")
 @WebServlet(name = "mailgun", value = "/send/email")
 public class MailgunServlet extends HttpServlet {
@@ -57,7 +56,7 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOEx
   }
 
   //CHECKSTYLE OFF: VariableDeclarationUsageDistance
-  // [START simple]
+  // [START gae_flex_mailgun_simple_message]
   private ClientResponse sendSimpleMessage(String recipient) {
     Client client = Client.create();
     client.addFilter(new HTTPBasicAuthFilter("api", MAILGUN_API_KEY));
@@ -71,9 +70,9 @@ private ClientResponse sendSimpleMessage(String recipient) {
     return webResource.type(MediaType.APPLICATION_FORM_URLENCODED).post(ClientResponse.class,
         formData);
   }
-  // [END simple]
+  // [END gae_flex_mailgun_simple_message]
 
-  // [START complex]
+  // [START gae_flex_mailgun_complex_message]
   private ClientResponse sendComplexMessage(String recipient) {
     Client client = Client.create();
     client.addFilter(new HTTPBasicAuthFilter("api", MAILGUN_API_KEY));
@@ -90,7 +89,6 @@ private ClientResponse sendComplexMessage(String recipient) {
     return webResource.type(MediaType.MULTIPART_FORM_DATA_TYPE)
         .post(ClientResponse.class, formData);
   }
-  // [END complex]
+  // [END gae_flex_mailgun_complex_message]
   //CHECKSTYLE ON: VariableDeclarationUsageDistance
 }
-// [END example]
diff --git a/flexible/mailjet/pom.xml b/flexible/mailjet/pom.xml
index e71bb60481f..e8b46412c0d 100644
--- a/flexible/mailjet/pom.xml
+++ b/flexible/mailjet/pom.xml
@@ -50,13 +50,13 @@
       <type>jar</type>
       <scope>provided</scope>
     </dependency>
-    <!-- [START dependencies] -->
+    <!-- [START gae_flex_mailjet_dependencies] -->
     <dependency>
       <groupId>com.mailjet</groupId>
       <artifactId>mailjet-client</artifactId>
       <version>${mailjet-version}</version>
     </dependency>
-    <!-- [END dependencies] -->
+    <!-- [END gae_flex_mailjet_dependencies] -->
   </dependencies>
   <build>
     <!-- for hot reload of the web application -->
diff --git a/flexible/mailjet/src/main/appengine/app.yaml b/flexible/mailjet/src/main/appengine/app.yaml
index a41ea04614a..8ecf1bb9370 100644
--- a/flexible/mailjet/src/main/appengine/app.yaml
+++ b/flexible/mailjet/src/main/appengine/app.yaml
@@ -5,8 +5,8 @@ handlers:
 - url: /.*
   script: this field is required, but ignored
 
-# [START env_variables]
+# [START gae_flex_mailjet_yaml]
 env_variables:
   MAILJET_API_KEY: YOUR-MAILJET-API-KEY
   MAILJET_SECRET_KEY: YOUR-MAILJET-SECRET-KEY
-# [END env_variables]
+# [END gae_flex_mailjet_yaml]
diff --git a/flexible/mailjet/src/main/java/com/example/mailjet/MailjetServlet.java b/flexible/mailjet/src/main/java/com/example/mailjet/MailjetServlet.java
index 3ba5e4f9d9b..96eba884e71 100644
--- a/flexible/mailjet/src/main/java/com/example/mailjet/MailjetServlet.java
+++ b/flexible/mailjet/src/main/java/com/example/mailjet/MailjetServlet.java
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-// [START mailjet_imports]
+// [START gae_flex_mailjet_config]
 
 package com.example.mailjet;
 
@@ -34,9 +34,9 @@
 import org.json.JSONArray;
 import org.json.JSONObject;
 
-// [END mailjet_imports]
+// [END gae_flex_mailjet_config]
 
-// [START app]
+// [START gae_flex_mailjet_send_message]
 @SuppressWarnings("serial")
 @WebServlet(name = "mailjet", value = "/send/email")
 public class MailjetServlet extends HttpServlet {
@@ -80,4 +80,4 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOEx
     }
   }
 }
-// [END app]
+// [END gae_flex_mailjet_send_message]
diff --git a/flexible/postgres/pom.xml b/flexible/postgres/pom.xml
index cd50869ec7a..4b650c62951 100644
--- a/flexible/postgres/pom.xml
+++ b/flexible/postgres/pom.xml
@@ -30,7 +30,7 @@
     <version>1.0.9</version>
   </parent>
 
-<!-- [START properties] -->
+<!-- [START gae_flex_postgres_properties] -->
   <properties>
 <!--
     INSTANCE_CONNECTION_NAME from Cloud Console > SQL > Instance Details > Properties
@@ -50,7 +50,7 @@
 <!-- [END_EXCLUDE] -->
     <sqlURL>jdbc:postgresql://google/${database}?useSSL=false&amp;socketFactoryArg=${INSTANCE_CONNECTION_NAME}&amp;socketFactory=com.google.cloud.sql.postgres.SocketFactory&amp;user=${user}&amp;password=${password}</sqlURL>
   </properties>
-<!-- [END properties] -->
+<!-- [END gae_flex_postgres_properties] -->
 
   <dependencies>
     <dependency>
@@ -75,7 +75,7 @@
       <type>jar</type>
       <scope>provided</scope>
     </dependency>
-    <!-- [START dependencies] -->
+    <!-- [START gae_flex_postgres_dependencies] -->
     <dependency>
       <groupId>org.postgresql</groupId>
       <artifactId>postgresql</artifactId>
@@ -87,17 +87,17 @@
       <artifactId>postgres-socket-factory</artifactId>
       <version>1.0.10</version>
     </dependency>
-    <!-- [END dependencies] -->
+    <!-- [END gae_flex_postgres_dependencies] -->
   </dependencies>
   <build>
-    <!-- [START resources] -->
+    <!-- [START gae_flex_postgres_resources] -->
     <resources>
       <resource>
         <directory>src/main/resources</directory>
         <filtering>true</filtering>
       </resource>
     </resources>
-    <!-- [END resources] -->
+    <!-- [END gae_flex_postgres_resources] -->
     <!-- for hot reload of the web application -->
     <outputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes</outputDirectory>
     <plugins>
diff --git a/flexible/postgres/src/main/java/com/example/postgres/PostgresSqlServlet.java b/flexible/postgres/src/main/java/com/example/postgres/PostgresSqlServlet.java
index 381757db852..3920af59efa 100644
--- a/flexible/postgres/src/main/java/com/example/postgres/PostgresSqlServlet.java
+++ b/flexible/postgres/src/main/java/com/example/postgres/PostgresSqlServlet.java
@@ -39,7 +39,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START example]
+// [START gae_flex_postgres_app]
 @SuppressWarnings("serial")
 @WebServlet(name = "postgresql", value = "")
 public class PostgresSqlServlet extends HttpServlet {
@@ -124,4 +124,4 @@ public void init() throws ServletException {
     }
   }
 }
-// [END example]
+// [END gae_flex_postgres_app]
diff --git a/flexible/pubsub/pom.xml b/flexible/pubsub/pom.xml
index 559f01583d1..4ab16e117d7 100644
--- a/flexible/pubsub/pom.xml
+++ b/flexible/pubsub/pom.xml
@@ -13,7 +13,6 @@
   See the License for the specific language governing permissions and
   limitations under the License.
 -->
-<!-- [START project] -->
 <project>
   <modelVersion>4.0.0</modelVersion>
   <packaging>war</packaging>
@@ -62,7 +61,6 @@
       <scope>provided</scope>
     </dependency>
 
-    <!-- [START dependencies] -->
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-pubsub</artifactId>
@@ -73,7 +71,6 @@
       <artifactId>google-cloud-datastore</artifactId>
       <version>1.38.0</version>
     </dependency>
-    <!-- [END dependencies] -->
 
     <!-- Test Dependencies -->
     <dependency>
@@ -122,4 +119,3 @@
     </plugins>
   </build>
 </project>
-<!-- [END project] -->
diff --git a/flexible/pubsub/src/main/appengine/app.yaml b/flexible/pubsub/src/main/appengine/app.yaml
index 5233b58b21c..4665b40ad36 100644
--- a/flexible/pubsub/src/main/appengine/app.yaml
+++ b/flexible/pubsub/src/main/appengine/app.yaml
@@ -10,7 +10,7 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
-# [START appyaml]
+
 runtime: java
 env: flex
 
@@ -18,9 +18,8 @@ handlers:
 - url: /.*
   script: this field is required, but ignored
 
-# [START env_variables]
+# [START gae_flex_pubsub_yaml]
 env_variables:
   PUBSUB_TOPIC: <your-topic-name>
   PUBSUB_VERIFICATION_TOKEN: <your-verification-token>
-# [END env_variables]
-# [END appyaml]
+# [END gae_flex_pubsub_yaml]
diff --git a/flexible/sendgrid/pom.xml b/flexible/sendgrid/pom.xml
index d149bf3a8f3..fea3f0a670b 100644
--- a/flexible/sendgrid/pom.xml
+++ b/flexible/sendgrid/pom.xml
@@ -48,13 +48,13 @@
       <type>jar</type>
       <scope>provided</scope>
     </dependency>
-    <!-- [START dependencies] -->
+    <!-- [START gae_flex_sendgrid_dependencies] -->
     <dependency>
       <groupId>com.sendgrid</groupId>
       <artifactId>sendgrid-java</artifactId>
       <version>2.2.2</version>
     </dependency>
-    <!-- [END dependencies] -->
+    <!-- [END gae_flex_sendgrid_dependencies] -->
   </dependencies>
   <build>
     <!-- for hot reload of the web application -->
diff --git a/flexible/sendgrid/src/main/appengine/app.yaml b/flexible/sendgrid/src/main/appengine/app.yaml
index 0efc5d7b4d2..431a03ca3e7 100644
--- a/flexible/sendgrid/src/main/appengine/app.yaml
+++ b/flexible/sendgrid/src/main/appengine/app.yaml
@@ -5,8 +5,8 @@ handlers:
 - url: /.*
   script: this field is required, but ignored
 
-# [START env_variables]
+# [START gae_flex_sendgrid_yaml]
 env_variables:
   SENDGRID_API_KEY: YOUR-SENDGRID-API-KEY
   SENDGRID_SENDER: YOUR-SENDGRID-SENDER
-# [END env_variables]
+# [END gae_flex_sendgrid_yaml]
diff --git a/flexible/sendgrid/src/main/java/com/example/sendgrid/SendEmailServlet.java b/flexible/sendgrid/src/main/java/com/example/sendgrid/SendEmailServlet.java
index 62084136490..7e2e43e53ed 100644
--- a/flexible/sendgrid/src/main/java/com/example/sendgrid/SendEmailServlet.java
+++ b/flexible/sendgrid/src/main/java/com/example/sendgrid/SendEmailServlet.java
@@ -27,7 +27,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START example]
+// [START gae_flex_sendgrid]
 @SuppressWarnings("serial")
 @WebServlet(name = "sendemail", value = "/send/email")
 public class SendEmailServlet extends HttpServlet {
@@ -63,4 +63,4 @@ public void service(HttpServletRequest req, HttpServletResponse resp) throws IOE
     }
   }
 }
-// [END example]
+// [END gae_flex_sendgrid]
diff --git a/flexible/twilio/pom.xml b/flexible/twilio/pom.xml
index 1c2a85b3301..a97e9bf2b6f 100644
--- a/flexible/twilio/pom.xml
+++ b/flexible/twilio/pom.xml
@@ -41,13 +41,13 @@
   </properties>
 
   <dependencies>
-    <!-- [START dependencies] -->
+    <!-- [START gae_flex_twilio_dependencies] -->
     <dependency>
       <groupId>com.twilio.sdk</groupId>
       <artifactId>twilio-java-sdk</artifactId>
       <version>6.3.0</version>
     </dependency>
-    <!-- [END dependencies] -->
+    <!-- [END gae_flex_twilio_dependencies] -->
     <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>javax.servlet-api</artifactId>
diff --git a/flexible/twilio/src/main/appengine/app.yaml b/flexible/twilio/src/main/appengine/app.yaml
index 1ee3836bcef..c1af1764ff7 100644
--- a/flexible/twilio/src/main/appengine/app.yaml
+++ b/flexible/twilio/src/main/appengine/app.yaml
@@ -5,9 +5,9 @@ handlers:
 - url: /.*
   script: this field is required, but ignored
 
-# [START env_variables]
+# [START gae_flex_twilio_env]
 env_variables:
   TWILIO_ACCOUNT_SID: YOUR-TWILIO-ACCOUNT-SID
   TWILIO_AUTH_TOKEN: YOUR-TWILIO-AUTH-TOKEN
   TWILIO_NUMBER: YOUR-TWILIO-NUMBER
-# [END env_variables]
+# [END gae_flex_twilio_env]
diff --git a/flexible/twilio/src/main/java/com/example/twilio/ReceiveCallServlet.java b/flexible/twilio/src/main/java/com/example/twilio/ReceiveCallServlet.java
index 48b22671dc9..53c8874afa9 100644
--- a/flexible/twilio/src/main/java/com/example/twilio/ReceiveCallServlet.java
+++ b/flexible/twilio/src/main/java/com/example/twilio/ReceiveCallServlet.java
@@ -26,7 +26,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START example]
+// [START gae_flex_twilio_receive_call]
 @SuppressWarnings("serial")
 @WebServlet(name = "receivecall", value = "/call/receive")
 public class ReceiveCallServlet extends HttpServlet {
@@ -46,4 +46,4 @@ public void service(HttpServletRequest req, HttpServletResponse resp) throws IOE
     resp.getWriter().print(twiml.toXML());
   }
 }
-// [END example]
+// [END gae_flex_twilio_receive_call]
diff --git a/flexible/twilio/src/main/java/com/example/twilio/ReceiveSmsServlet.java b/flexible/twilio/src/main/java/com/example/twilio/ReceiveSmsServlet.java
index f13d774c18f..65f99333bca 100644
--- a/flexible/twilio/src/main/java/com/example/twilio/ReceiveSmsServlet.java
+++ b/flexible/twilio/src/main/java/com/example/twilio/ReceiveSmsServlet.java
@@ -26,7 +26,7 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-// [START example]
+// [START gae_flex_twilio_receive_sms]
 @SuppressWarnings("serial")
 @WebServlet(name = "receivesms", value = "/sms/receive")
 public class ReceiveSmsServlet extends HttpServlet {
@@ -50,4 +50,4 @@ public void service(HttpServletRequest request, HttpServletResponse response) th
     response.getWriter().print(twiml.toXML());
   }
 }
-// [END example]
+// [END gae_flex_twilio_receive_sms]
diff --git a/flexible/twilio/src/main/java/com/example/twilio/SendSmsServlet.java b/flexible/twilio/src/main/java/com/example/twilio/SendSmsServlet.java
index 3c54f9eb3ae..1fc2ff12418 100644
--- a/flexible/twilio/src/main/java/com/example/twilio/SendSmsServlet.java
+++ b/flexible/twilio/src/main/java/com/example/twilio/SendSmsServlet.java
@@ -32,7 +32,7 @@
 import org.apache.http.NameValuePair;
 import org.apache.http.message.BasicNameValuePair;
 
-// [START example]
+// [START gae_flex_twilio_send_sms]
 @SuppressWarnings("serial")
 @WebServlet(name = "sendsms", value = "/sms/send")
 public class SendSmsServlet extends HttpServlet {
@@ -64,4 +64,4 @@ public void service(HttpServletRequest req, HttpServletResponse resp) throws IOE
     }
   }
 }
-// [END example]
+// [END gae_flex_twilio_send_sms]