diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 59ead256874..2185ef6d5e7 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,7 +1,7 @@
 How to contribute
 ==================
 Thank you for wanting to contribute to Spine. The following links will help you get started:
- * [Wiki home][wiki-home] — the home of the developer's documentation.
+ * [Wiki home][wiki-home] — the home of the framework developer's documentation.
  * [Getting started with Spine in Java][quick-start] — this guide will walk you through
    a minimal client-server “Hello World!” application in Java. 
  * [Introduction][docs-intro] — this section of the Spine Documentation will help you understand
@@ -9,20 +9,19 @@ Thank you for wanting to contribute to Spine. The following links will help you
    
 Pull requests
 -------------
-A work on an improvement starts from creating an issue which describes a bug or a feature you
-intend to fix. The issue will be used for communications on the proposed improvements. If code
-changes are going to be introduced, the issue would also have a link to corresponding Pull Request.
+The work on an improvement starts with creating an issue that describes a bug or a feature. The issue will be used for communications on the proposed improvements. 
+If code changes are going to be introduced, the issue should also have a link to the corresponding Pull Request.
 
 Code contributions should:
   * Be accompanied by tests.
-  * Be licensed Apache 2.0 with the appropriate copyright header for each file.
+  * Be licensed under the Apache v2.0 license with the appropriate copyright header for each file.
   * Formatted according to the code style. See [Wiki home][wiki-home] for the links to
     style guides of the programming languages used in the framework.  
 
 Contributor License Agreement
 -----------------------------
 Contributions to the code of Spine Event Engine framework and its libraries must be accompanied by
-Contributor License Agreement.  
+Contributor License Agreement (CLA).
 
  * If you are an individual writing original source code and you're sure you own
    the intellectual property, then you'll need to sign an individual CLA.
diff --git a/client/src/main/java/io/spine/client/CommandRequest.java b/client/src/main/java/io/spine/client/CommandRequest.java
index 7286485a319..f57e8c45715 100644
--- a/client/src/main/java/io/spine/client/CommandRequest.java
+++ b/client/src/main/java/io/spine/client/CommandRequest.java
@@ -171,13 +171,27 @@ public CommandRequest onServerError(ServerErrorHandler handler) {
      *         client code "knows" how many of them it expects. Also, some events may not arrive
      *         because of communication or business logic reasons. That's why the returned
      *         subscriptions should be cancelled by the client code when it no longer needs it.
+     * @see #postAndForget()
      */
-    @CanIgnoreReturnValue
     public ImmutableSet<Subscription> post() {
         PostOperation op = new PostOperation();
         return op.perform();
     }
 
+    /**
+     * Posts the command without subscribing to events that may be generated during
+     * the command handling.
+     *
+     * @throws IllegalStateException
+     *         if {@link #observe(Class, EventConsumer)} or {@link #observe(Class, Consumer)} were
+     *         called in the command request configuration chain before calling this method
+     * @see #post()
+     */
+    public void postAndForget() throws IllegalStateException {
+        PostOperation op = new PostOperation();
+        op.performWithoutSubscriptions();
+    }
+
     @VisibleForTesting
     CommandMessage message() {
         return message;
@@ -201,9 +215,41 @@ private PostOperation() {
         }
 
         private ImmutableSet<Subscription> perform() {
+            if (consumers.isEmpty()) {
+                throw newIllegalStateException(
+                        "No event subscriptions were requested prior to calling `post()`." +
+                        " If you intend to receive events please call `observe()`" +
+                                " before `post()`." +
+                        " Or, if you subscribe to events or projections elsewhere," +
+                                " please use `postAndForget()`."
+                );
+            }
             subscribeToEvents();
             Ack ack = client().post(command);
             Status status = ack.getStatus();
+            return handleStatus(status);
+        }
+
+        private void performWithoutSubscriptions() {
+            if (!consumers.isEmpty()) {
+                throw newIllegalStateException(
+                        "Subscriptions to events were requested. Please call `post()` instead."
+                );
+            }
+            Ack ack = client().post(command);
+            Status status = ack.getStatus();
+            handleStatus(status);
+        }
+
+        private void subscribeToEvents() {
+            Client client = client();
+            this.subscriptions = subscribe(client, command, consumers, streamingErrorHandler());
+            client.subscriptions()
+                  .addAll(subscriptions);
+        }
+
+        @CanIgnoreReturnValue
+        private ImmutableSet<Subscription> handleStatus(Status status) {
             switch (status.getStatusCase()) {
                 case OK:
                     return Optional.ofNullable(subscriptions)
@@ -224,21 +270,13 @@ private ImmutableSet<Subscription> perform() {
             }
         }
 
-        private void subscribeToEvents() {
-            Client client = client();
-            this.subscriptions = subscribe(client, command, consumers, streamingErrorHandler());
-            checkNotNull(subscriptions);
-            client.subscriptions()
-                  .addAll(subscriptions);
-        }
-
         /**
          * Cancels the passed subscriptions to events because the command could not be posted.
          *
          */
         private void cancelVoidSubscriptions() {
-            Subscriptions activeSubscriptions = client().subscriptions();
             if (subscriptions != null) {
+                Subscriptions activeSubscriptions = client().subscriptions();
                 subscriptions.forEach(activeSubscriptions::cancel);
             }
         }
diff --git a/client/src/main/java/io/spine/client/EventsAfterCommand.java b/client/src/main/java/io/spine/client/EventsAfterCommand.java
index 3234b05622f..447bd674a00 100644
--- a/client/src/main/java/io/spine/client/EventsAfterCommand.java
+++ b/client/src/main/java/io/spine/client/EventsAfterCommand.java
@@ -29,6 +29,7 @@
 import io.spine.core.EventContext;
 import io.spine.core.UserId;
 import io.spine.logging.Logging;
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -47,7 +48,7 @@ final class EventsAfterCommand implements Logging {
     private final Command command;
     private final MultiEventConsumers consumers;
 
-    static ImmutableSet<Subscription>
+    static @NonNull ImmutableSet<Subscription>
     subscribe(Client client,
               Command command,
               MultiEventConsumers consumers,
diff --git a/client/src/main/java/io/spine/client/MultiEventConsumers.java b/client/src/main/java/io/spine/client/MultiEventConsumers.java
index fd683910ff9..7237b01036c 100644
--- a/client/src/main/java/io/spine/client/MultiEventConsumers.java
+++ b/client/src/main/java/io/spine/client/MultiEventConsumers.java
@@ -63,8 +63,17 @@ ImmutableSet<Class<? extends EventMessage>> eventTypes() {
         return map.keySet();
     }
 
+    /**
+     * Returns {@code true} if no event consumers were collected, {@code false} otherwise.
+     */
+    boolean isEmpty() {
+        boolean result = eventTypes().isEmpty();
+        return result;
+    }
+
     /** Obtains all the consumers grouped by type of consumed events. */
     ImmutableMap<Class<? extends EventMessage>, StreamObserver<Event>> toObservers() {
+        @SuppressWarnings("ConstantConditions") // `null` values are prevented when gathering.
         Map<Class<? extends EventMessage>, StreamObserver<Event>> observers =
                 Maps.transformValues(map, EventConsumers::toObserver);
         return ImmutableMap.copyOf(observers);
diff --git a/client/src/main/java/io/spine/client/Subscriptions.java b/client/src/main/java/io/spine/client/Subscriptions.java
index a5415ddabd5..ceb538403f8 100644
--- a/client/src/main/java/io/spine/client/Subscriptions.java
+++ b/client/src/main/java/io/spine/client/Subscriptions.java
@@ -22,6 +22,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.flogger.FluentLogger;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.protobuf.Message;
 import io.grpc.ManagedChannel;
 import io.grpc.stub.StreamObserver;
@@ -34,7 +35,6 @@
 import io.spine.logging.Logging;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-import java.util.Collection;
 import java.util.HashSet;
 import java.util.Optional;
 import java.util.Set;
@@ -172,7 +172,7 @@ <M extends Message> Subscription subscribeTo(Topic topic, StreamObserver<M> obse
     }
 
     /** Adds all the passed subscriptions. */
-    void addAll(Collection<Subscription> newSubscriptions) {
+    void addAll(Iterable<Subscription> newSubscriptions) {
         newSubscriptions.forEach(this::add);
     }
 
@@ -188,6 +188,7 @@ private void add(Subscription s) {
      *
      * @return {@code true} if the subscription was previously made
      */
+    @CanIgnoreReturnValue
     public boolean cancel(Subscription s) {
         checkNotNull(s);
         boolean isActive = items.contains(s);
diff --git a/license-report.md b/license-report.md
index f5a2b03bc0a..f800f3111c6 100644
--- a/license-report.md
+++ b/license-report.md
@@ -1,6 +1,6 @@
 
     
-# Dependencies of `io.spine:spine-client:1.5.20`
+# Dependencies of `io.spine:spine-client:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -324,6 +324,7 @@
 1. **Group:** org.jacoco **Name:** org.jacoco.report **Version:** 0.8.5
      * **POM License: Eclipse Public License 2.0** - [https://www.eclipse.org/legal/epl-2.0/](https://www.eclipse.org/legal/epl-2.0/)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -405,12 +406,12 @@
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:39 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Fri Aug 14 14:46:46 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-core:1.5.20`
+# Dependencies of `io.spine:spine-core:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.code.findbugs **Name:** jsr305 **Version:** 3.0.2
@@ -694,6 +695,7 @@ This report was generated on **Fri Jun 19 14:07:39 EEST 2020** using [Gradle-Lic
 1. **Group:** org.jacoco **Name:** org.jacoco.report **Version:** 0.8.5
      * **POM License: Eclipse Public License 2.0** - [https://www.eclipse.org/legal/epl-2.0/](https://www.eclipse.org/legal/epl-2.0/)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -775,12 +777,12 @@ This report was generated on **Fri Jun 19 14:07:39 EEST 2020** using [Gradle-Lic
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:40 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Fri Aug 14 14:46:46 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine.tools:spine-model-assembler:1.5.20`
+# Dependencies of `io.spine.tools:spine-model-assembler:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -1099,6 +1101,7 @@ This report was generated on **Fri Jun 19 14:07:40 EEST 2020** using [Gradle-Lic
 1. **Group:** org.jacoco **Name:** org.jacoco.report **Version:** 0.8.5
      * **POM License: Eclipse Public License 2.0** - [https://www.eclipse.org/legal/epl-2.0/](https://www.eclipse.org/legal/epl-2.0/)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -1180,12 +1183,12 @@ This report was generated on **Fri Jun 19 14:07:40 EEST 2020** using [Gradle-Lic
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:40 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Fri Aug 14 14:46:47 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine.tools:spine-model-verifier:1.5.20`
+# Dependencies of `io.spine.tools:spine-model-verifier:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -1570,6 +1573,7 @@ This report was generated on **Fri Jun 19 14:07:40 EEST 2020** using [Gradle-Lic
      * **POM License: Eclipse Public License version 1.0** - [http://www.eclipse.org/legal/epl-v10.html](http://www.eclipse.org/legal/epl-v10.html)
      * **POM License: Public Domain** - [http://repository.jboss.org/licenses/cc0-1.0.txt](http://repository.jboss.org/licenses/cc0-1.0.txt)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit-pioneer **Name:** junit-pioneer **Version:** 0.4.2
      * **POM Project URL:** [https://github.com/junit-pioneer/junit-pioneer](https://github.com/junit-pioneer/junit-pioneer)
      * **POM License: The MIT License** - [https://github.com/junit-pioneer/junit-pioneer/blob/master/LICENSE](https://github.com/junit-pioneer/junit-pioneer/blob/master/LICENSE)
@@ -1655,12 +1659,12 @@ This report was generated on **Fri Jun 19 14:07:40 EEST 2020** using [Gradle-Lic
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:41 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Fri Aug 14 14:46:47 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-server:1.5.20`
+# Dependencies of `io.spine:spine-server:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -1996,6 +2000,7 @@ This report was generated on **Fri Jun 19 14:07:41 EEST 2020** using [Gradle-Lic
 1. **Group:** org.jacoco **Name:** org.jacoco.report **Version:** 0.8.5
      * **POM License: Eclipse Public License 2.0** - [https://www.eclipse.org/legal/epl-2.0/](https://www.eclipse.org/legal/epl-2.0/)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -2077,12 +2082,12 @@ This report was generated on **Fri Jun 19 14:07:41 EEST 2020** using [Gradle-Lic
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:42 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Fri Aug 14 14:46:47 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-testutil-client:1.5.20`
+# Dependencies of `io.spine:spine-testutil-client:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -2215,6 +2220,7 @@ This report was generated on **Fri Jun 19 14:07:42 EEST 2020** using [Gradle-Lic
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -2454,6 +2460,7 @@ This report was generated on **Fri Jun 19 14:07:42 EEST 2020** using [Gradle-Lic
 1. **Group:** org.jacoco **Name:** org.jacoco.report **Version:** 0.8.5
      * **POM License: Eclipse Public License 2.0** - [https://www.eclipse.org/legal/epl-2.0/](https://www.eclipse.org/legal/epl-2.0/)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -2535,12 +2542,12 @@ This report was generated on **Fri Jun 19 14:07:42 EEST 2020** using [Gradle-Lic
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:44 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Fri Aug 14 14:46:49 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-testutil-core:1.5.20`
+# Dependencies of `io.spine:spine-testutil-core:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -2673,6 +2680,7 @@ This report was generated on **Fri Jun 19 14:07:44 EEST 2020** using [Gradle-Lic
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -2920,6 +2928,7 @@ This report was generated on **Fri Jun 19 14:07:44 EEST 2020** using [Gradle-Lic
 1. **Group:** org.jacoco **Name:** org.jacoco.report **Version:** 0.8.5
      * **POM License: Eclipse Public License 2.0** - [https://www.eclipse.org/legal/epl-2.0/](https://www.eclipse.org/legal/epl-2.0/)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -3001,12 +3010,12 @@ This report was generated on **Fri Jun 19 14:07:44 EEST 2020** using [Gradle-Lic
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:45 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Fri Aug 14 14:46:50 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-testutil-server:1.5.20`
+# Dependencies of `io.spine:spine-testutil-server:1.5.24`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -3139,6 +3148,7 @@ This report was generated on **Fri Jun 19 14:07:45 EEST 2020** using [Gradle-Lic
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -3422,6 +3432,7 @@ This report was generated on **Fri Jun 19 14:07:45 EEST 2020** using [Gradle-Lic
 1. **Group:** org.jacoco **Name:** org.jacoco.report **Version:** 0.8.5
      * **POM License: Eclipse Public License 2.0** - [https://www.eclipse.org/legal/epl-2.0/](https://www.eclipse.org/legal/epl-2.0/)
 
+1. **Group:** org.junit **Name:** junit-bom **Version:** 5.6.2 **No license information found**
 1. **Group:** org.junit.jupiter **Name:** junit-jupiter-api **Version:** 5.6.2
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
@@ -3503,4 +3514,4 @@ This report was generated on **Fri Jun 19 14:07:45 EEST 2020** using [Gradle-Lic
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Fri Jun 19 14:07:48 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
\ No newline at end of file
+This report was generated on **Fri Aug 14 14:46:51 EEST 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index 886cc359469..eea537e584a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,7 +12,7 @@ all modules and does not describe the project structure per-subproject.
 
 <groupId>io.spine</groupId>
 <artifactId>spine-core-java</artifactId>
-<version>1.5.21</version>
+<version>1.5.24</version>
 
 <inceptionYear>2015</inceptionYear>
 
@@ -70,25 +70,25 @@ all modules and does not describe the project structure per-subproject.
   <dependency>
     <groupId>io.spine</groupId>
     <artifactId>spine-base</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
     <scope>compile</scope>
   </dependency>
   <dependency>
     <groupId>io.spine</groupId>
     <artifactId>spine-time</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.21</version>
     <scope>compile</scope>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-model-compiler</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
     <scope>compile</scope>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-plugin-base</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
     <scope>compile</scope>
   </dependency>
   <dependency>
@@ -130,25 +130,25 @@ all modules and does not describe the project structure per-subproject.
   <dependency>
     <groupId>io.spine</groupId>
     <artifactId>spine-testlib</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
     <scope>test</scope>
   </dependency>
   <dependency>
     <groupId>io.spine</groupId>
     <artifactId>spine-testutil-time</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.21</version>
     <scope>test</scope>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-mute-logging</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
     <scope>test</scope>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-plugin-testlib</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
     <scope>test</scope>
   </dependency>
   <dependency>
@@ -204,12 +204,12 @@ all modules and does not describe the project structure per-subproject.
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-javadoc-filter</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-protoc-plugin</artifactId>
-    <version>1.5.19</version>
+    <version>1.5.23</version>
   </dependency>
   <dependency>
     <groupId>net.sourceforge.pmd</groupId>
diff --git a/server/src/test/java/io/spine/client/ClientTest.java b/server/src/test/java/io/spine/client/ClientTest.java
index b861f914edf..8ea6623d1f9 100644
--- a/server/src/test/java/io/spine/client/ClientTest.java
+++ b/server/src/test/java/io/spine/client/ClientTest.java
@@ -177,7 +177,7 @@ void byId() {
                                          .build();
             client.asGuest()
                   .command(command)
-                  .post();
+                  .postAndForget();
             ImmutableList<ActiveUsers> users =
                     client.onBehalfOf(user)
                           .select(ActiveUsers.class)
diff --git a/server/src/test/java/io/spine/client/CommandRequestTest.java b/server/src/test/java/io/spine/client/CommandRequestTest.java
index 8a36b3df5ac..41d2b05b95d 100644
--- a/server/src/test/java/io/spine/client/CommandRequestTest.java
+++ b/server/src/test/java/io/spine/client/CommandRequestTest.java
@@ -45,6 +45,7 @@
 
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.extensions.proto.ProtoTruth.assertThat;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 @MuteLogging
@@ -78,139 +79,182 @@ protected ImmutableList<BoundedContextBuilder> contexts() {
         return ImmutableList.of(ClientTestContext.users());
     }
 
-    @Test
-    @DisplayName("deliver an event to a consumer")
-    void eventConsumer() {
-        commandRequest.observe(UserLoggedIn.class, counter::add)
-                      .observe(UserAccountCreated.class, counter::add)
-                      .post();
-        assertThat(counter.containsAll(UserLoggedIn.class, UserAccountCreated.class))
-                .isTrue();
-    }
-
-    @Test
-    @DisplayName("deliver an event and its context to a consumer")
-    void eventAndContextConsumer() {
-        commandRequest.observe(UserLoggedIn.class, (e, c) -> counter.add(e))
-                      .observe(UserAccountCreated.class, (e, c) -> counter.add(e))
-                      .post();
-        assertThat(counter.containsAll(UserLoggedIn.class, UserAccountCreated.class))
-                .isTrue();
-    }
-
-    @Test
-    @DisplayName("deliver a rejection to its consumers")
-    void rejections() {
-        // Post the command so that the user is logged in. We are not interested in events here.
-        commandRequest.post();
-        // Now post the command again, expecting the rejection.
-        commandRequest.observe(UserAlreadyLoggedIn.class, counter::add)
-                      .post();
-
-        assertThat(counter.contains(UserAlreadyLoggedIn.class))
-                .isTrue();
-    }
-
     @Nested
-    @DisplayName("Allow setting custom streaming error handler")
-    class CustomStreamingErrorHandler {
+    @DisplayName("Allow posting without subscriptions")
+    class NoSubscriptions {
 
         @Test
-        @DisplayName("rejecting `null`")
-        void rejectingNull() {
-            assertThrows(NullPointerException.class, () -> commandRequest.onStreamingError(null));
+        @DisplayName("Rejecting when a subscription was made")
+        void illegalUse() {
+            commandRequest.observe(UserLoggedIn.class, counter::add);
+            assertThrows(
+                    IllegalStateException.class,
+                    () -> commandRequest.postAndForget()
+            );
+        }
+
+        @Test
+        @DisplayName("Delivering no events")
+        void noEvents() {
+            assertDoesNotThrow(() -> commandRequest.postAndForget());
         }
     }
 
     @Nested
-    @DisplayName("Allow setting custom consumer error handler")
-    class CustomConsumerErrorHandler {
+    @DisplayName("Deliver")
+    class OfDelivery {
 
-        private boolean handlerInvoked;
-        private @Nullable Throwable passedThrowable;
-
-        @BeforeEach
-        void setup() {
-            handlerInvoked = false;
-            passedThrowable = null;
+        @Test
+        @DisplayName("an event to a consumer")
+        void eventConsumer() {
+            commandRequest.observe(UserLoggedIn.class, counter::add)
+                          .observe(UserAccountCreated.class, counter::add)
+                          .post();
+            assertDelivered(UserLoggedIn.class, UserAccountCreated.class);
         }
 
         @Test
-        @DisplayName("rejecting `null`")
-        void rejectingNull() {
-            assertThrows(NullPointerException.class, () -> commandRequest.onConsumingError(null));
+        @DisplayName("an event and its context to a consumer")
+        void eventAndContextConsumer() {
+            commandRequest.observe(UserLoggedIn.class, (e, c) -> counter.add(e))
+                          .observe(UserAccountCreated.class, (e, c) -> counter.add(e))
+                          .post();
+            assertDelivered(UserLoggedIn.class, UserAccountCreated.class);
         }
 
         @Test
-        @DisplayName("invoking the handler when a consumer fails")
-        void invocation() {
-            ConsumerErrorHandler<EventMessage> handler = (c, th) -> {
-                handlerInvoked = true;
-                passedThrowable = th;
-            };
-            RuntimeException exception = new RuntimeException("Consumer-generated error.");
-
-            commandRequest.onConsumingError(handler)
-                          .observe(UserLoggedIn.class, e -> {
-                              throw exception;
-                          })
+        @DisplayName("a rejection to its consumers")
+        void rejections() {
+            // Post the command so that the user is logged in. We are not interested in events here.
+            commandRequest.postAndForget();
+            // Now post the command again, expecting the rejection.
+            commandRequest.observe(UserAlreadyLoggedIn.class, counter::add)
                           .post();
 
-            assertThat(handlerInvoked)
+            assertDelivered(UserAlreadyLoggedIn.class);
+        }
+
+        @SafeVarargs
+        private final void assertDelivered(Class<? extends EventMessage>... classes) {
+            assertThat(counter.containsAll(classes))
                     .isTrue();
-            assertThat(passedThrowable)
-                    .isEqualTo(exception);
         }
     }
 
+    @Test
+    @DisplayName("Suggest `postAndForget()` call if no subscriptions were made")
+    void noSubscriptions() {
+        assertThrows(
+                IllegalStateException.class,
+                () -> commandRequest.post()
+        );
+    }
+
     @Nested
-    @DisplayName("Allow setting custom posting error handler")
-    class CustomServerErrorHandler {
+    @DisplayName("Support custom error handler for")
+    class OfErrorHandler {
 
-        private @Nullable Message postedMessage;
-        private @Nullable Error returnedError;
+        @Nested
+        @DisplayName("streaming error")
+        class CustomStreamingErrorHandler {
 
-        @BeforeEach
-        void setup() {
-            postedMessage = null;
-            returnedError = null;
+            @Test
+            @DisplayName("rejecting `null`")
+            void rejectingNull() {
+                assertThrows(NullPointerException.class, () -> commandRequest.onStreamingError(null));
+            }
         }
 
-        @Test
-        @DisplayName("rejecting `null`")
-        void rejectingNull() {
-            assertThrows(NullPointerException.class, () -> commandRequest.onServerError(null));
+        @Nested
+        @DisplayName("consumer error")
+        class CustomConsumerErrorHandler {
+
+            private boolean handlerInvoked;
+            private @Nullable Throwable passedThrowable;
+
+            @BeforeEach
+            void setup() {
+                handlerInvoked = false;
+                passedThrowable = null;
+            }
+
+            @Test
+            @DisplayName("rejecting `null`")
+            void rejectingNull() {
+                assertThrows(NullPointerException.class, () -> commandRequest.onConsumingError(null));
+            }
+
+            @Test
+            @DisplayName("invoking the handler when a consumer fails")
+            void invocation() {
+                ConsumerErrorHandler<EventMessage> handler = (c, th) -> {
+                    handlerInvoked = true;
+                    passedThrowable = th;
+                };
+                RuntimeException exception = new RuntimeException("Consumer-generated error.");
+
+                commandRequest.onConsumingError(handler)
+                              .observe(UserLoggedIn.class, e -> {
+                                  throw exception;
+                              })
+                              .post();
+
+                assertThat(handlerInvoked)
+                        .isTrue();
+                assertThat(passedThrowable)
+                        .isEqualTo(exception);
+            }
         }
 
-        @Test
-        @DisplayName("invoking handler when an invalid command posted")
-        void invocation() {
-            ServerErrorHandler handler = (message, error) -> {
-                postedMessage = message;
-                returnedError = error;
-            };
-
-            UnsupportedCommand commandMessage = UnsupportedCommand
-                    .newBuilder()
-                    .setUser(GivenUserId.generated())
-                    .build();
-            CommandRequest request =
-                    client().asGuest()
-                            .command(commandMessage)
-                            .onServerError(handler);
-            request.post();
-
-            assertThat(returnedError)
-                    .isNotNull();
-            assertThat(postedMessage)
-                    .isInstanceOf(Command.class);
-            Command expected = Command
-                    .newBuilder()
-                    .setMessage(AnyPacker.pack(commandMessage))
-                    .build();
-            assertThat(postedMessage)
-                    .comparingExpectedFieldsOnly()
-                    .isEqualTo(expected);
+        @Nested
+        @DisplayName("posting error")
+        class CustomServerErrorHandler {
+
+            private @Nullable Message postedMessage;
+            private @Nullable Error returnedError;
+
+            @BeforeEach
+            void setup() {
+                postedMessage = null;
+                returnedError = null;
+            }
+
+            @Test
+            @DisplayName("rejecting `null`")
+            void rejectingNull() {
+                assertThrows(NullPointerException.class, () -> commandRequest.onServerError(null));
+            }
+
+            @Test
+            @DisplayName("invoking handler when an invalid command posted")
+            void invocation() {
+                ServerErrorHandler handler = (message, error) -> {
+                    postedMessage = message;
+                    returnedError = error;
+                };
+
+                UnsupportedCommand commandMessage = UnsupportedCommand
+                        .newBuilder()
+                        .setUser(GivenUserId.generated())
+                        .build();
+                CommandRequest request =
+                        client().asGuest()
+                                .command(commandMessage)
+                                .onServerError(handler);
+                request.postAndForget();
+
+                assertThat(returnedError)
+                        .isNotNull();
+                assertThat(postedMessage)
+                        .isInstanceOf(Command.class);
+                Command expected = Command
+                        .newBuilder()
+                        .setMessage(AnyPacker.pack(commandMessage))
+                        .build();
+                assertThat(postedMessage)
+                        .comparingExpectedFieldsOnly()
+                        .isEqualTo(expected);
+            }
         }
     }
 }
diff --git a/server/src/test/java/io/spine/client/EventSubscriptionRequestTest.java b/server/src/test/java/io/spine/client/EventSubscriptionRequestTest.java
index e43e3ef3f15..1e01b956fe8 100644
--- a/server/src/test/java/io/spine/client/EventSubscriptionRequestTest.java
+++ b/server/src/test/java/io/spine/client/EventSubscriptionRequestTest.java
@@ -85,7 +85,7 @@ void observeEventMessage() {
                 .subscribeToEvent(UserLoggedIn.class)
                 .observe(counter::add)
                 .post();
-        commandRequest.post();
+        commandRequest.postAndForget();
 
         assertThat(counter.contains(UserLoggedIn.class))
             .isTrue();
@@ -113,7 +113,7 @@ void subscribeWithFiltering() {
                         rememberedContext = c;
                     })
                     .post();
-            commandRequest.post();
+            commandRequest.postAndForget();
         }
 
         @Test
diff --git a/version.gradle.kts b/version.gradle.kts
index 7df954d300b..f276dd5c548 100644
--- a/version.gradle.kts
+++ b/version.gradle.kts
@@ -25,6 +25,6 @@
  * as we want to manage the versions in a single source.
  */
 
-val spineBaseVersion: String by extra("1.5.21")
+val spineBaseVersion: String by extra("1.5.23")
 val spineTimeVersion: String by extra("1.5.21")
-val versionToPublish: String by extra("1.5.23")
+val versionToPublish: String by extra("1.5.24")