diff --git a/samples/snippets/src/main/java/com/example/firestore/Quickstart.java b/samples/snippets/src/main/java/com/example/firestore/Quickstart.java
index ffbc1f355..f53cd27a3 100644
--- a/samples/snippets/src/main/java/com/example/firestore/Quickstart.java
+++ b/samples/snippets/src/main/java/com/example/firestore/Quickstart.java
@@ -20,8 +20,10 @@
 import com.google.auth.oauth2.GoogleCredentials;
 import com.google.cloud.firestore.DocumentReference;
 // [START fs_include_dependencies]
+// [START firestore_setup_dependencies]
 import com.google.cloud.firestore.Firestore;
 import com.google.cloud.firestore.FirestoreOptions;
+// [END firestore_setup_dependencies]
 // [END fs_include_dependencies]
 import com.google.cloud.firestore.QueryDocumentSnapshot;
 import com.google.cloud.firestore.QuerySnapshot;
@@ -44,19 +46,23 @@ public class Quickstart {
    */
   public Quickstart() {
     // [START fs_initialize]
+    // [START firestore_setup_client_create]
     Firestore db = FirestoreOptions.getDefaultInstance().getService();
+    // [END firestore_setup_client_create]
     // [END fs_initialize]
     this.db = db;
   }
 
   public Quickstart(String projectId) throws Exception {
     // [START fs_initialize_project_id]
+    // [START firestore_setup_client_create_with_project_id]
     FirestoreOptions firestoreOptions =
         FirestoreOptions.getDefaultInstance().toBuilder()
             .setProjectId(projectId)
             .setCredentials(GoogleCredentials.getApplicationDefault())
             .build();
     Firestore db = firestoreOptions.getService();
+    // [END firestore_setup_client_create_with_project_id]
     // [END fs_initialize_project_id]
     this.db = db;
   }
@@ -74,6 +80,7 @@ void addDocument(String docName) throws Exception {
     switch (docName) {
       case "alovelace": {
         // [START fs_add_data_1]
+        // [START firestore_setup_dataset_pt1]
         DocumentReference docRef = db.collection("users").document("alovelace");
         // Add document data  with id "alovelace" using a hashmap
         Map<String, Object> data = new HashMap<>();
@@ -85,11 +92,13 @@ void addDocument(String docName) throws Exception {
         // ...
         // result.get() blocks on response
         System.out.println("Update time : " + result.get().getUpdateTime());
+        // [END firestore_setup_dataset_pt1]
         // [END fs_add_data_1]
         break;
       }
       case "aturing": {
         // [START fs_add_data_2]
+        // [START firestore_setup_dataset_pt2]
         DocumentReference docRef = db.collection("users").document("aturing");
         // Add document data with an additional field ("middle")
         Map<String, Object> data = new HashMap<>();
@@ -100,6 +109,7 @@ void addDocument(String docName) throws Exception {
 
         ApiFuture<WriteResult> result = docRef.set(data);
         System.out.println("Update time : " + result.get().getUpdateTime());
+        // [END firestore_setup_dataset_pt2]
         // [END fs_add_data_2]
         break;
       }
diff --git a/samples/snippets/src/main/java/com/example/firestore/snippets/ListenDataSnippets.java b/samples/snippets/src/main/java/com/example/firestore/snippets/ListenDataSnippets.java
index dc4958737..8bc9bc146 100644
--- a/samples/snippets/src/main/java/com/example/firestore/snippets/ListenDataSnippets.java
+++ b/samples/snippets/src/main/java/com/example/firestore/snippets/ListenDataSnippets.java
@@ -54,6 +54,7 @@ Map<String, Object> listenToDocument() throws Exception {
     final SettableApiFuture<Map<String, Object>> future = SettableApiFuture.create();
 
     // [START listen_to_document]
+    // [START firestore_listen_document]
     DocumentReference docRef = db.collection("cities").document("SF");
     docRef.addSnapshotListener(new EventListener<DocumentSnapshot>() {
       @Override
@@ -76,6 +77,7 @@ public void onEvent(@Nullable DocumentSnapshot snapshot,
         // [END_EXCLUDE]
       }
     });
+    // [END firestore_listen_document]
     // [END listen_to_document]
 
     return future.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
@@ -88,6 +90,7 @@ List<String> listenForMultiple() throws Exception {
     final SettableApiFuture<List<String>> future = SettableApiFuture.create();
 
     // [START listen_to_multiple]
+    // [START firestore_listen_query_snapshots]
     db.collection("cities")
         .whereEqualTo("state", "CA")
         .addSnapshotListener(new EventListener<QuerySnapshot>() {
@@ -113,6 +116,7 @@ public void onEvent(@Nullable QuerySnapshot snapshots,
             // [END_EXCLUDE]
           }
         });
+    // [END firestore_listen_query_snapshots]
     // [END listen_to_multiple]
 
     return future.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
@@ -125,6 +129,7 @@ List<DocumentChange> listenForChanges() throws Exception {
     SettableApiFuture<List<DocumentChange>> future = SettableApiFuture.create();
 
     // [START listen_for_changes]
+    // [START firestore_listen_query_changes]
     db.collection("cities")
         .whereEqualTo("state", "CA")
         .addSnapshotListener(new EventListener<QuerySnapshot>() {
@@ -158,6 +163,7 @@ public void onEvent(@Nullable QuerySnapshot snapshots,
             // [END_EXCLUDE]
           }
         });
+    // [END firestore_listen_query_changes]
     // [END listen_for_changes]
 
     return future.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
@@ -168,6 +174,7 @@ public void onEvent(@Nullable QuerySnapshot snapshots,
    */
   void detachListener() {
     // [START detach_errors]
+    // [START firestore_listen_detach]
     Query query = db.collection("cities");
     ListenerRegistration registration = query.addSnapshotListener(
         new EventListener<QuerySnapshot>() {
@@ -184,6 +191,7 @@ public void onEvent(@Nullable QuerySnapshot snapshots,
 
     // Stop listening to changes
     registration.remove();
+    // [END firestore_listen_detach]
     // [END detach_errors]
   }
 
@@ -192,6 +200,7 @@ public void onEvent(@Nullable QuerySnapshot snapshots,
    */
   void listenErrors() {
     // [START listen_errors]
+    // [START firestore_listen_handle_error]
     db.collection("cities")
         .addSnapshotListener(new EventListener<QuerySnapshot>() {
           @Override
@@ -209,6 +218,7 @@ public void onEvent(@Nullable QuerySnapshot snapshots,
             }
           }
         });
+    // [END firestore_listen_handle_error]
     // [END listen_errors]
   }
 
diff --git a/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java b/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java
index 7a9b4f527..926d9c019 100644
--- a/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java
+++ b/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java
@@ -53,6 +53,7 @@ class ManageDataSnippets {
    */
   Map<String, Object> addSimpleDocumentAsMap() throws Exception {
     // [START fs_add_doc_as_map]
+    // [START firestore_data_set_from_map]
     // Create a Map to store the data we want to set
     Map<String, Object> docData = new HashMap<>();
     docData.put("name", "Los Angeles");
@@ -64,6 +65,7 @@ Map<String, Object> addSimpleDocumentAsMap() throws Exception {
     // ...
     // future.get() blocks on response
     System.out.println("Update time : " + future.get().getUpdateTime());
+    // [END firestore_data_set_from_map]
     // [END fs_add_doc_as_map]
     return docData;
   }
@@ -75,6 +77,7 @@ Map<String, Object> addSimpleDocumentAsMap() throws Exception {
    */
   Map<String, Object> addDocumentWithDifferentDataTypes() throws Exception {
     // [START fs_add_doc_data_types]
+    // [START firestore_data_set_from_map_nested]
     Map<String, Object> docData = new HashMap<>();
     docData.put("stringExample", "Hello, World");
     docData.put("booleanExample", false);
@@ -93,6 +96,7 @@ Map<String, Object> addDocumentWithDifferentDataTypes() throws Exception {
 
     ApiFuture<WriteResult> future = db.collection("data").document("one").set(docData);
     System.out.println("Update time : " + future.get().getUpdateTime());
+    // [END firestore_data_set_from_map_nested]
     // [END fs_add_doc_data_types]
 
     return docData;
@@ -105,11 +109,13 @@ Map<String, Object> addDocumentWithDifferentDataTypes() throws Exception {
    */
   City addSimpleDocumentAsEntity() throws Exception {
     // [START fs_add_simple_doc_as_entity]
+    // [START firestore_data_set_from_custom_type]
     City city = new City("Los Angeles", "CA", "USA", false, 3900000L,
         Arrays.asList("west_coast", "socal"));
     ApiFuture<WriteResult> future = db.collection("cities").document("LA").set(city);
     // block on response if required
     System.out.println("Update time : " + future.get().getUpdateTime());
+    // [END firestore_data_set_from_custom_type]
     // [END fs_add_simple_doc_as_entity]
 
     return city;
@@ -120,7 +126,9 @@ City addSimpleDocumentAsEntity() throws Exception {
    */
   void setRequiresId(Map<String, String> data) {
     // [START fs_set_requires_id]
+    // [START firestore_data_set_id_specified]
     db.collection("cities").document("new-city-id").set(data);
+    // [END firestore_data_set_id_specified]
     // [END fs_set_requires_id]
   }
 
@@ -132,12 +140,14 @@ void setRequiresId(Map<String, String> data) {
    */
   String addDocumentDataWithAutoGeneratedId() throws Exception {
     // [START fs_add_doc_data_with_auto_id]
+    // [START firestore_data_set_id_random_collection]
     // Add document data with auto-generated id.
     Map<String, Object> data = new HashMap<>();
     data.put("name", "Tokyo");
     data.put("country", "Japan");
     ApiFuture<DocumentReference> addedDocRef = db.collection("cities").add(data);
     System.out.println("Added document with ID: " + addedDocRef.get().getId());
+    // [END firestore_data_set_id_random_collection]
     // [END fs_add_doc_data_with_auto_id]
 
     return addedDocRef.get().getId();
@@ -152,12 +162,14 @@ String addDocumentDataAfterAutoGeneratingId() throws Exception {
     City data = new City();
 
     // [START fs_add_doc_data_after_auto_id]
+    // [START firestore_data_set_id_random_document_ref]
     // Add document data after generating an id.
     DocumentReference addedDocRef = db.collection("cities").document();
     System.out.println("Added document with ID: " + addedDocRef.getId());
 
     // later...
     ApiFuture<WriteResult> writeResult = addedDocRef.set(data);
+    // [END firestore_data_set_id_random_document_ref]
     // [END fs_add_doc_data_after_auto_id]
 
     // writeResult.get() blocks on operation
@@ -169,6 +181,7 @@ String addDocumentDataAfterAutoGeneratingId() throws Exception {
   void updateSimpleDocument() throws Exception {
     db.collection("cities").document("DC").set(new City("Washington D.C.")).get();
     // [START fs_update_doc]
+    // [START firestore_data_set_field]
     // Update an existing document
     DocumentReference docRef = db.collection("cities").document("DC");
 
@@ -178,6 +191,7 @@ void updateSimpleDocument() throws Exception {
     // ...
     WriteResult result = future.get();
     System.out.println("Write result: " + result);
+    // [END firestore_data_set_field]
     // [END fs_update_doc]
   }
 
@@ -203,6 +217,7 @@ void updateUsingMap() throws Exception {
   /** Partially update fields of a document using a map (field => value). */
   void updateAndCreateIfMissing() throws Exception {
     // [START fs_update_create_if_missing]
+    // [START firestore_data_set_doc_upsert]
     //asynchronously update doc, create the document if missing
     Map<String, Object> update = new HashMap<>();
     update.put("capital", true);
@@ -214,6 +229,7 @@ void updateAndCreateIfMissing() throws Exception {
             .set(update, SetOptions.merge());
     // ...
     System.out.println("Update time : " + writeResult.get().getUpdateTime());
+    // [END firestore_data_set_doc_upsert]
     // [END fs_update_create_if_missing]
   }
 
@@ -221,6 +237,7 @@ void updateAndCreateIfMissing() throws Exception {
   void updateNestedFields() throws Exception {
     //CHECKSTYLE OFF: VariableDeclarationUsageDistance
     // [START fs_update_nested_fields]
+    // [START firestore_data_set_nested_fields]
     // Create an initial document to update
     DocumentReference frankDocRef = db.collection("users").document("frank");
     Map<String, Object> initialData = new HashMap<>();
@@ -246,6 +263,7 @@ void updateNestedFields() throws Exception {
     ApiFuture<WriteResult> writeResult = frankDocRef.update(updates);
     // ...
     System.out.println("Update time : " + writeResult.get().getUpdateTime());
+    // [END firestore_data_set_nested_fields]
     // [END fs_update_nested_fields]
     //CHECKSTYLE ON: VariableDeclarationUsageDistance
   }
@@ -255,16 +273,19 @@ void updateServerTimestamp() throws Exception {
     db.collection("objects").document("some-id").set(new HashMap<String, Object>()).get();
 
     // [START fs_update_server_timestamp]
+    // [START firestore_data_set_server_timestamp]
     DocumentReference docRef = db.collection("objects").document("some-id");
     // Update the timestamp field with the value from the server
     ApiFuture<WriteResult> writeResult = docRef.update("timestamp", FieldValue.serverTimestamp());
     System.out.println("Update time : " + writeResult.get());
+    // [END firestore_data_set_server_timestamp]
     // [END fs_update_server_timestamp]
   }
 
   /** Update array fields in a document. **/
   void updateDocumentArray() throws Exception {
     // [START fs_update_document_array]
+    // [START firestore_data_set_array_operations]
     DocumentReference washingtonRef = db.collection("cities").document("DC");
 
     // Atomically add a new region to the "regions" array field.
@@ -276,6 +297,7 @@ void updateDocumentArray() throws Exception {
     ApiFuture<WriteResult> arrayRm = washingtonRef.update("regions",
         FieldValue.arrayRemove("east_coast"));
     System.out.println("Update time : " + arrayRm.get());
+    // [END firestore_data_set_array_operations]
     // [END fs_update_document_array]
   }
 
@@ -286,12 +308,14 @@ void deleteFields() throws Exception {
     db.collection("cities").document("BJ").set(city).get();
 
     // [START fs_delete_fields]
+    // [START firestore_data_delete_field]
     DocumentReference docRef = db.collection("cities").document("BJ");
     Map<String, Object> updates = new HashMap<>();
     updates.put("capital", FieldValue.delete());
     // Update and delete the "capital" field in the document
     ApiFuture<WriteResult> writeResult = docRef.update(updates);
     System.out.println("Update time : " + writeResult.get());
+    // [END firestore_data_delete_field]
     // [END fs_delete_fields]
   }
 
@@ -299,14 +323,17 @@ void deleteFields() throws Exception {
   void deleteDocument() throws Exception {
     db.collection("cities").document("DC").set(new City("Washington, D.C.")).get();
     // [START fs_delete_doc]
+    // [START firestore_data_delete_doc]
     // asynchronously delete a document
     ApiFuture<WriteResult> writeResult = db.collection("cities").document("DC").delete();
     // ...
     System.out.println("Update time : " + writeResult.get().getUpdateTime());
+    // [END firestore_data_delete_doc]
     // [END fs_delete_doc]
   }
 
   // [START fs_delete_collection]
+  // [START firestore_data_delete_collection]
   /** Delete a collection in batches to avoid out-of-memory errors.
    * Batch size may be tuned based on document size (atmost 1MB) and application requirements.
    */
@@ -329,6 +356,7 @@ void deleteCollection(CollectionReference collection, int batchSize) {
       System.err.println("Error deleting collection : " + e.getMessage());
     }
   }
+  // [END firestore_data_delete_collection]
   // [END fs_delete_collection]
 
   /** Run a simple transaction to perform a field value increment.
@@ -337,6 +365,7 @@ void deleteCollection(CollectionReference collection, int batchSize) {
    */
   ApiFuture<Void> runSimpleTransaction() throws Exception {
     // [START fs_run_simple_transaction]
+    // [START firestore_transaction_document_update]
     // Initialize doc
     final DocumentReference docRef = db.collection("cities").document("SF");
     City city = new City("SF");
@@ -353,6 +382,7 @@ ApiFuture<Void> runSimpleTransaction() throws Exception {
       return null;
     });
     // block on transaction operation using transaction.get()
+    // [END firestore_transaction_document_update]
     // [END fs_run_simple_transaction]
     return futureTransaction;
   }
@@ -369,6 +399,7 @@ String returnInfoFromTransaction(long population) throws Exception {
     // Block until transaction is complete is using transaction.get()
     db.collection("cities").document("SF").set(map).get();
     // [START fs_return_info_transaction]
+    // [START firestore_transaction_document_update_conditional]
     final DocumentReference docRef = db.collection("cities").document("SF");
     ApiFuture<String> futureTransaction = db.runTransaction(transaction -> {
       DocumentSnapshot snapshot = transaction.get(docRef).get();
@@ -383,6 +414,7 @@ String returnInfoFromTransaction(long population) throws Exception {
     });
     // Print information retrieved from transaction
     System.out.println(futureTransaction.get());
+    // [END firestore_transaction_document_update_conditional]
     // [END fs_return_info_transaction]
     return futureTransaction.get();
   }
@@ -393,6 +425,7 @@ void writeBatch() throws Exception {
     db.collection("cities").document("LA").set(new City()).get();
 
     // [START fs_write_batch]
+    // [START firestore_data_batch_writes]
     // Get a new write batch
     WriteBatch batch = db.batch();
 
@@ -415,6 +448,7 @@ void writeBatch() throws Exception {
     for (WriteResult result :future.get()) {
       System.out.println("Update time : " + result.getUpdateTime());
     }
+    // [END firestore_data_batch_writes]
     // [END fs_write_batch]
   }
 
@@ -424,11 +458,13 @@ public void updateDocumentIncrement() throws ExecutionException, InterruptedExce
     db.collection("cities").document("DC").set(city).get();
 
     // [START fs_update_document_increment]
+    // [START firestore_data_set_numeric_increment]
     DocumentReference washingtonRef = db.collection("cities").document("DC");
 
     // Atomically increment the population of the city by 50.
     final ApiFuture<WriteResult> updateFuture = washingtonRef
         .update("population", FieldValue.increment(50));
+    // [END firestore_data_set_numeric_increment]
     // [END fs_update_document_increment]
     updateFuture.get();
   }
diff --git a/samples/snippets/src/main/java/com/example/firestore/snippets/QueryDataSnippets.java b/samples/snippets/src/main/java/com/example/firestore/snippets/QueryDataSnippets.java
index 20ce9cc29..ee9c5a93c 100644
--- a/samples/snippets/src/main/java/com/example/firestore/snippets/QueryDataSnippets.java
+++ b/samples/snippets/src/main/java/com/example/firestore/snippets/QueryDataSnippets.java
@@ -52,6 +52,7 @@ class QueryDataSnippets {
   void prepareExamples() throws Exception {
 
     // [START fs_query_create_examples]
+    // [START firestore_query_filter_dataset]
     CollectionReference cities = db.collection("cities");
     List<ApiFuture<WriteResult>> futures = new ArrayList<>();
     futures.add(
@@ -101,6 +102,7 @@ void prepareExamples() throws Exception {
                     Arrays.asList("jingjinji", "hebei"))));
     // (optional) block on documents successfully added
     ApiFutures.allAsList(futures).get();
+    // [END firestore_query_filter_dataset]
     // [END fs_query_create_examples]
   }
 
@@ -111,6 +113,7 @@ void prepareExamples() throws Exception {
    */
   Query createAQuery() throws Exception {
     // [START fs_create_query]
+    // [START firestore_query_filter_eq_boolean]
     // Create a reference to the cities collection
     CollectionReference cities = db.collection("cities");
     // Create a query against the collection.
@@ -121,6 +124,7 @@ Query createAQuery() throws Exception {
     for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
       System.out.println(document.getId());
     }
+    // [END firestore_query_filter_eq_boolean]
     // [END fs_create_query]
     return query;
   }
@@ -132,6 +136,7 @@ Query createAQuery() throws Exception {
    */
   Query createAQueryAlternate() throws Exception {
     // [START fs_create_query_country]
+    // [START firestore_query_filter_eq_string]
     // Create a reference to the cities collection
     CollectionReference cities = db.collection("cities");
     // Create a query against the collection.
@@ -142,6 +147,7 @@ Query createAQueryAlternate() throws Exception {
     for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
       System.out.println(document.getId());
     }
+    // [END firestore_query_filter_eq_string]
     // [END fs_create_query_country]
     return query;
   }
@@ -156,9 +162,11 @@ List<Query> createSimpleQueries() {
     CollectionReference cities = db.collection("cities");
 
     // [START fs_simple_queries]
+    // [START firestore_query_filter_single_examples]
     Query stateQuery = cities.whereEqualTo("state", "CA");
     Query populationQuery = cities.whereLessThan("population", 1000000L);
     Query nameQuery = cities.whereGreaterThanOrEqualTo("name", "San Francisco");
+    // [END firestore_query_filter_single_examples]
     // [END fs_simple_queries]
 
     querys.add(stateQuery);
@@ -174,8 +182,10 @@ List<Query> createSimpleQueries() {
    */
   Query createArrayQuery() {
     // [START fs_array_contains_filter]
+    // [START firestore_query_filter_array_contains]
     CollectionReference citiesRef = db.collection("cities");
     Query westCoastQuery = citiesRef.whereArrayContains("regions", "west_coast");
+    // [END firestore_query_filter_array_contains]
     // [END fs_array_contains_filter]
 
     return westCoastQuery;
@@ -191,7 +201,9 @@ Query createArrayQuery() {
   Query createChainedQuery() {
     CollectionReference cities = db.collection("cities");
     // [START fs_chained_query]
+    // [START firestore_query_filter_compound_multi_eq]
     Query chainedQuery1 = cities.whereEqualTo("state", "CO").whereEqualTo("name", "Denver");
+    // [END firestore_query_filter_compound_multi_eq]
     // [END fs_chained_query]
     return chainedQuery1;
   }
@@ -205,7 +217,9 @@ Query createChainedQuery() {
   Query createCompositeIndexChainedQuery() {
     CollectionReference cities = db.collection("cities");
     // [START fs_composite_index_chained_query]
+    // [START firestore_query_filter_compound_multi_eq_lt]
     Query chainedQuery2 = cities.whereEqualTo("state", "CA").whereLessThan("population", 1000000L);
+    // [END firestore_query_filter_compound_multi_eq_lt]
     // [END fs_composite_index_chained_query]
     return chainedQuery2;
   }
@@ -218,9 +232,11 @@ Query createCompositeIndexChainedQuery() {
   Query createRangeQuery() {
     CollectionReference cities = db.collection("cities");
     // [START fs_range_query]
+    // [START firestore_query_filter_range_valid]
     Query validQuery1 =
         cities.whereGreaterThanOrEqualTo("state", "CA").whereLessThanOrEqualTo("state", "IN");
     Query validQuery2 = cities.whereEqualTo("state", "CA").whereGreaterThan("population", 1000000);
+    // [END firestore_query_filter_range_valid]
     // [END fs_range_query]
     return validQuery1;
   }
@@ -234,8 +250,10 @@ Query createInvalidRangeQuery() {
     CollectionReference cities = db.collection("cities");
     // Violates constraint : range operators are limited to a single field
     // [START fs_invalid_range_query]
+    // [START firestore_query_filter_range_invalid]
     Query invalidRangeQuery =
         cities.whereGreaterThanOrEqualTo("state", "CA").whereGreaterThan("population", 100000);
+    // [END firestore_query_filter_range_invalid]
     // [END fs_invalid_range_query]
     return invalidRangeQuery;
   }
@@ -248,7 +266,9 @@ Query createInvalidRangeQuery() {
   Query createOrderByNameWithLimitQuery() {
     CollectionReference cities = db.collection("cities");
     // [START fs_order_by_name_limit_query]
+    // [START firestore_query_order_limit]
     Query query = cities.orderBy("name").limit(3);
+    // [END firestore_query_order_limit]
     // [END fs_order_by_name_limit_query]
     return query;
   }
@@ -261,7 +281,9 @@ Query createOrderByNameWithLimitQuery() {
   Query createOrderByNameWithLimitToLastQuery() {
     CollectionReference cities = db.collection("cities");
     // [START fs_order_by_name_limit_query]
+    // [START firestore_query_order_limit]
     Query query = cities.orderBy("name").limitToLast(3);
+    // [END firestore_query_order_limit]
     // [END fs_order_by_name_limit_query]
     return query;
   }
@@ -274,7 +296,9 @@ Query createOrderByNameWithLimitToLastQuery() {
   Query createOrderByCountryAndPopulation() {
     CollectionReference cities = db.collection("cities");
     // [START fs_order_by_country_population]
+    // [START firestore_query_order_multi]
     Query query = cities.orderBy("state").orderBy("population", Direction.DESCENDING);
+    // [END firestore_query_order_multi]
     // [END fs_order_by_country_population]
     return query;
   }
@@ -287,7 +311,9 @@ Query createOrderByCountryAndPopulation() {
   Query createOrderByNameDescWithLimitQuery() {
     CollectionReference cities = db.collection("cities");
     // [START fs_order_by_name_desc_limit_query]
+    // [START firestore_query_order_desc_limit]
     Query query = cities.orderBy("name", Direction.DESCENDING).limit(3);
+    // [END firestore_query_order_desc_limit]
     // [END fs_order_by_name_desc_limit_query]
     return query;
   }
@@ -300,7 +326,9 @@ Query createOrderByNameDescWithLimitQuery() {
   Query createWhereWithOrderByAndLimitQuery() {
     CollectionReference cities = db.collection("cities");
     // [START fs_where_order_by_limit_query]
+    // [START firestore_query_order_limit_field_valid]
     Query query = cities.whereGreaterThan("population", 2500000L).orderBy("population").limit(2);
+    // [END firestore_query_order_limit_field_valid]
     // [END fs_where_order_by_limit_query]
     return query;
   }
@@ -329,7 +357,9 @@ Query createInvalidRangeWithOrderByQuery() {
     CollectionReference cities = db.collection("cities");
     // Violates the constraint that range and order by are required to be on the same field
     // [START fs_invalid_range_order_by_query]
+    // [START firestore_query_order_field_invalid]
     Query query = cities.whereGreaterThan("population", 2500000L).orderBy("country");
+    // [END firestore_query_order_field_invalid]
     // [END fs_invalid_range_order_by_query]
     return query;
   }
@@ -342,7 +372,9 @@ Query createInvalidRangeWithOrderByQuery() {
   Query createStartAtFieldQueryCursor() {
     CollectionReference cities = db.collection("cities");
     // [START fs_start_at_field_query_cursor]
+    // [START firestore_query_cursor_start_at_field_value_single]
     Query query = cities.orderBy("population").startAt(4921000L);
+    // [END firestore_query_cursor_start_at_field_value_single]
     // [END fs_start_at_field_query_cursor]
     return query;
   }
@@ -355,7 +387,9 @@ Query createStartAtFieldQueryCursor() {
   Query createEndAtFieldQueryCursor() {
     CollectionReference cities = db.collection("cities");
     // [START fs_end_at_field_query_cursor]
+    // [START firestore_query_cursor_end_at_field_value_single]
     Query query = cities.orderBy("population").endAt(4921000L);
+    // [END firestore_query_cursor_end_at_field_value_single]
     // [END fs_end_at_field_query_cursor]
     return query;
   }
@@ -363,12 +397,14 @@ Query createEndAtFieldQueryCursor() {
   /* Create queries with multiple cursor conditions. */
   void createMultipleCursorConditionsQuery() {
     // [START fs_multiple_cursor_conditions]
+    // [START firestore_query_cursor_start_at_field_value_multi]
     // Will return all Springfields
     Query query1 = db.collection("cities").orderBy("name").orderBy("state").startAt("Springfield");
 
     // Will return "Springfield, Missouri" and "Springfield, Wisconsin"
     Query query2 =
         db.collection("cities").orderBy("name").orderBy("state").startAt("Springfield", "Missouri");
+    // [END firestore_query_cursor_start_at_field_value_multi]
     // [END fs_multiple_cursor_conditions]
   }
 
@@ -380,12 +416,14 @@ void createMultipleCursorConditionsQuery() {
   Query createStartAtSnapshotQueryCursor()
       throws InterruptedException, ExecutionException, TimeoutException {
     // [START fs_document_snapshot_cursor]
+    // [START firestore_query_cursor_start_at_document]
     // Fetch the snapshot with an API call, waiting for a maximum of 30 seconds for a result.
     ApiFuture<DocumentSnapshot> future = db.collection("cities").document("SF").get();
     DocumentSnapshot snapshot = future.get(30, TimeUnit.SECONDS);
 
     // Construct the query
     Query query = db.collection("cities").orderBy("population").startAt(snapshot);
+    // [END firestore_query_cursor_start_at_document]
     // [END fs_document_snapshot_cursor]
     return query;
   }
@@ -393,6 +431,7 @@ Query createStartAtSnapshotQueryCursor()
   /** Example of a paginated query. */
   List<Query> paginateCursor() throws InterruptedException, ExecutionException, TimeoutException {
     // [START fs_paginate_cursor]
+    // [START firestore_query_cursor_pagination]
     // Construct query for first 25 cities, ordered by population.
     CollectionReference cities = db.collection("cities");
     Query firstPage = cities.orderBy("population").limit(25);
@@ -407,6 +446,7 @@ List<Query> paginateCursor() throws InterruptedException, ExecutionException, Ti
 
     future = secondPage.get();
     docs = future.get(30, TimeUnit.SECONDS).getDocuments();
+    // [END firestore_query_cursor_pagination]
     // [END fs_paginate_cursor]
     return Arrays.asList(firstPage, secondPage);
   }
@@ -415,6 +455,7 @@ void collectionGroupQuery() throws ExecutionException, InterruptedException {
     // CHECKSTYLE OFF: Indentation
     // CHECKSTYLE OFF: RightCurlyAlone
     // [START fs_collection_group_query_data_setup]
+    // [START firestore_query_collection_group_dataset]
     CollectionReference cities = db.collection("cities");
 
     final List<ApiFuture<WriteResult>> futures =
@@ -530,14 +571,17 @@ void collectionGroupQuery() throws ExecutionException, InterruptedException {
                       }
                     }));
     final List<WriteResult> landmarks = ApiFutures.allAsList(futures).get();
+    // [END firestore_query_collection_group_dataset]
     // [END fs_collection_group_query_data_setup]
 
     // [START fs_collection_group_query]
+    // [START firestore_query_collection_group_filter_eq]
     final Query museums = db.collectionGroup("landmarks").whereEqualTo("type", "museum");
     final ApiFuture<QuerySnapshot> querySnapshot = museums.get();
     for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
       System.out.println(document.getId());
     }
+    // [END firestore_query_collection_group_filter_eq]
     // [END fs_collection_group_query]
     // CHECKSTYLE ON: RightCurlyAlone
     // CHECKSTYLE ON: Indentation
@@ -545,48 +589,58 @@ void collectionGroupQuery() throws ExecutionException, InterruptedException {
 
   public Query arrayContainsAnyQueries() {
     // [START fs_query_filter_array_contains_any]
+    // [START firestore_query_filter_array_contains_any]
     CollectionReference citiesRef = db.collection("cities");
 
     Query query =
         citiesRef.whereArrayContainsAny("regions", Arrays.asList("west_coast", "east_coast"));
+    // [END firestore_query_filter_array_contains_any]
     // [END fs_query_filter_array_contains_any]
     return query;
   }
 
   public Query inQueryWithoutArray() {
     // [START fs_query_filter_in]
+    // [START firestore_query_filter_in]
     CollectionReference citiesRef = db.collection("cities");
 
     Query query = citiesRef.whereIn("country", Arrays.asList("USA", "Japan"));
+    // [END firestore_query_filter_in]
     // [END fs_query_filter_in]
     return query;
   }
 
   public Query inQueryWithArray() {
     // [START fs_query_filter_in_with_array]
+    // [START firestore_query_filter_in_with_array]
     CollectionReference citiesRef = db.collection("cities");
 
     Query query =
         citiesRef.whereIn(
             "regions", Arrays.asList(Arrays.asList("west_coast"), Arrays.asList("east_coast")));
+    // [END firestore_query_filter_in_with_array]
     // [END fs_query_filter_in_with_array]
     return query;
   }
 
   Query notEqualsQuery() {
     // [START fs_query_not_equals]
+    // [START firestore_query_filter_not_eq]
     CollectionReference citiesRef = db.collection("cities");
 
     Query query = citiesRef.whereNotEqualTo("capital", false);
+    // [END firestore_query_filter_not_eq]
     // [END fs_query_not_equals]
     return query;
   }
 
   Query filterNotIn() {
     // [START fs_filter_not_in]
+    // [START firestore_query_filter_not_in]
     CollectionReference citiesRef = db.collection("cities");
 
     Query query = citiesRef.whereNotIn("country", Arrays.asList("USA", "Japan"));
+    // [END firestore_query_filter_not_in]
     // [END fs_filter_not_in]
     return query;
   }
diff --git a/samples/snippets/src/main/java/com/example/firestore/snippets/References.java b/samples/snippets/src/main/java/com/example/firestore/snippets/References.java
index afa2d7506..ea28e6c8b 100644
--- a/samples/snippets/src/main/java/com/example/firestore/snippets/References.java
+++ b/samples/snippets/src/main/java/com/example/firestore/snippets/References.java
@@ -36,8 +36,10 @@ public References(Firestore db) {
    */
   public CollectionReference getACollectionRef() {
     // [START fs_collection_ref]
+    // [START firestore_data_reference_collection]
     // Reference to the collection "users"
     CollectionReference collection = db.collection("users");
+    // [END firestore_data_reference_collection]
     // [END fs_collection_ref]
     return collection;
   }
@@ -49,8 +51,10 @@ public CollectionReference getACollectionRef() {
    */
   public DocumentReference getADocumentRef() {
     // [START fs_document_ref]
+    // [START firestore_data_reference_document]
     // Reference to a document with id "alovelace" in the collection "users"
     DocumentReference document = db.collection("users").document("alovelace");
+    // [END firestore_data_reference_document]
     // [END fs_document_ref]
     return document;
   }
@@ -62,8 +66,10 @@ public DocumentReference getADocumentRef() {
    */
   public DocumentReference getADocumentRefUsingPath() {
     // [START fs_document_path_ref]
+    // [START firestore_data_reference_document_path]
     // Reference to a document with id "alovelace" in the collection "users"
     DocumentReference document = db.document("users/alovelace");
+    // [END firestore_data_reference_document_path]
     // [END fs_document_path_ref]
     return document;
   }
@@ -75,9 +81,11 @@ public DocumentReference getADocumentRefUsingPath() {
    */
   public DocumentReference getASubCollectionDocumentRef() {
     // [START fs_subcollection_ref]
+    // [START firestore_data_reference_subcollection]
     // Reference to a document in subcollection "messages"
     DocumentReference document =
         db.collection("rooms").document("roomA").collection("messages").document("message1");
+    // [END firestore_data_reference_subcollection]
     // [END fs_subcollection_ref]
     return document;
   }
diff --git a/samples/snippets/src/main/java/com/example/firestore/snippets/RetrieveDataSnippets.java b/samples/snippets/src/main/java/com/example/firestore/snippets/RetrieveDataSnippets.java
index d89a1fb6d..3e9afb137 100644
--- a/samples/snippets/src/main/java/com/example/firestore/snippets/RetrieveDataSnippets.java
+++ b/samples/snippets/src/main/java/com/example/firestore/snippets/RetrieveDataSnippets.java
@@ -43,6 +43,7 @@ public class RetrieveDataSnippets {
   /** Create cities collection and add sample documents. */
   void prepareExamples() throws Exception {
     // [START fs_retrieve_create_examples]
+    // [START firestore_data_get_dataset]
     CollectionReference cities = db.collection("cities");
     List<ApiFuture<WriteResult>> futures = new ArrayList<>();
     futures.add(cities.document("SF").set(new City("San Francisco", "CA", "USA", false, 860000L,
@@ -57,6 +58,7 @@ void prepareExamples() throws Exception {
         Arrays.asList("jingjinji", "hebei"))));
     // (optional) block on operation
     ApiFutures.allAsList(futures).get();
+    // [END firestore_data_get_dataset]
     // [END fs_retrieve_create_examples]
   }
 
@@ -67,6 +69,7 @@ void prepareExamples() throws Exception {
    */
   public Map<String, Object> getDocumentAsMap() throws Exception {
     // [START fs_get_doc_as_map]
+    // [START firestore_data_get_as_map]
     DocumentReference docRef = db.collection("cities").document("SF");
     // asynchronously retrieve the document
     ApiFuture<DocumentSnapshot> future = docRef.get();
@@ -78,6 +81,7 @@ public Map<String, Object> getDocumentAsMap() throws Exception {
     } else {
       System.out.println("No such document!");
     }
+    // [END firestore_data_get_as_map]
     // [END fs_get_doc_as_map]
     return (document.exists()) ? document.getData() : null;
   }
@@ -89,6 +93,7 @@ public Map<String, Object> getDocumentAsMap() throws Exception {
    */
   public City getDocumentAsEntity() throws Exception {
     // [START fs_get_doc_as_entity]
+    // [START firestore_data_get_as_custom_type]
     DocumentReference docRef = db.collection("cities").document("BJ");
     // asynchronously retrieve the document
     ApiFuture<DocumentSnapshot> future = docRef.get();
@@ -102,6 +107,7 @@ public City getDocumentAsEntity() throws Exception {
     } else {
       System.out.println("No such document!");
     }
+    // [END firestore_data_get_as_custom_type]
     // [END fs_get_doc_as_entity]
     return city;
   }
@@ -113,6 +119,7 @@ public City getDocumentAsEntity() throws Exception {
    */
   public List<QueryDocumentSnapshot> getQueryResults() throws Exception {
     // [START fs_get_multiple_docs]
+    // [START firestore_data_query]
     //asynchronously retrieve multiple documents
     ApiFuture<QuerySnapshot> future =
         db.collection("cities").whereEqualTo("capital", true).get();
@@ -121,6 +128,7 @@ public List<QueryDocumentSnapshot> getQueryResults() throws Exception {
     for (DocumentSnapshot document : documents) {
       System.out.println(document.getId() + " => " + document.toObject(City.class));
     }
+    // [END firestore_data_query]
     // [END fs_get_multiple_docs]
     return documents;
   }
@@ -132,6 +140,7 @@ public List<QueryDocumentSnapshot> getQueryResults() throws Exception {
    */
   public List<QueryDocumentSnapshot> getAllDocuments() throws Exception {
     // [START fs_get_all_docs]
+    // [START firestore_data_get_all_documents]
     //asynchronously retrieve all documents
     ApiFuture<QuerySnapshot> future = db.collection("cities").get();
     // future.get() blocks on response
@@ -139,6 +148,7 @@ public List<QueryDocumentSnapshot> getAllDocuments() throws Exception {
     for (QueryDocumentSnapshot document : documents) {
       System.out.println(document.getId() + " => " + document.toObject(City.class));
     }
+    // [END firestore_data_get_all_documents]
     // [END fs_get_all_docs]
     return documents;
   }
@@ -150,12 +160,14 @@ public List<QueryDocumentSnapshot> getAllDocuments() throws Exception {
    */
   public Iterable<CollectionReference> listCollections() throws Exception {
     // [START fs_get_collections]
+    // [START firestore_data_get_sub_collections]
     Iterable<CollectionReference> collections =
         db.collection("cities").document("SF").listCollections();
 
     for (CollectionReference collRef : collections) {
       System.out.println("Found subcollection with id: " + collRef.getId());
     }
+    // [END firestore_data_get_sub_collections]
     // [END fs_get_collections]
     return collections;
   }
diff --git a/samples/snippets/src/main/java/com/example/firestore/snippets/model/City.java b/samples/snippets/src/main/java/com/example/firestore/snippets/model/City.java
index 48a41145a..e48400f5f 100644
--- a/samples/snippets/src/main/java/com/example/firestore/snippets/model/City.java
+++ b/samples/snippets/src/main/java/com/example/firestore/snippets/model/City.java
@@ -30,6 +30,7 @@ public class City {
   private List<String> regions;
 
   // [START fs_class_definition]
+  // [START firestore_data_custom_type_definition]
   public City() {
     // Must have a public no-argument constructor
   }
@@ -44,6 +45,7 @@ public City(String name, String state, String country,
     this.population = population;
     this.regions = regions;
   }
+  // [END firestore_data_custom_type_definition]
   // [END fs_class_definition]
 
   public City(String name) {