diff --git a/core/src/main/java/io/github/mmm/base/exception/ApplicationException.java b/core/src/main/java/io/github/mmm/base/exception/ApplicationException.java
index 77cbd6d..fc2cf94 100644
--- a/core/src/main/java/io/github/mmm/base/exception/ApplicationException.java
+++ b/core/src/main/java/io/github/mmm/base/exception/ApplicationException.java
@@ -57,7 +57,7 @@ public ApplicationException(Localizable message) {
    * The constructor.
    *
    * @param message the {@link #getMessage() message} describing the problem briefly.
-   * @param cause is the {@link #getCause() cause} of this exception.
+   * @param cause the {@link #getCause() cause} of this exception.
    */
   public ApplicationException(String message, Throwable cause) {
 
@@ -67,8 +67,8 @@ public ApplicationException(String message, Throwable cause) {
   /**
    * The constructor.
    *
-   * @param message the {@link #getLocalizedMessage() message} describing the problem briefly.
-   * @param cause is the {@link #getCause() cause} of this exception.
+   * @param message the {@link #getNlsMessage() NLS message} describing the problem briefly.
+   * @param cause the {@link #getCause() cause} of this exception.
    */
   public ApplicationException(Localizable message, Throwable cause) {
 
@@ -79,7 +79,7 @@ public ApplicationException(Localizable message, Throwable cause) {
    * The constructor.
    *
    * @param message the {@link #getMessage() message} describing the problem briefly.
-   * @param cause is the {@link #getCause() cause} of this exception. May be <code>null</code>.
+   * @param cause the {@link #getCause() cause} of this exception. May be <code>null</code>.
    * @param uuid the explicit {@link #getUuid() UUID} or <code>null</code> to initialize by default (from given
    *        {@link Throwable} or as new {@link UUID}).
    */
@@ -91,8 +91,8 @@ protected ApplicationException(String message, Throwable cause, UUID uuid) {
   /**
    * The constructor.
    *
-   * @param message the {@link #getLocalizedMessage() message} describing the problem briefly.
-   * @param cause is the {@link #getCause() cause} of this exception. May be <code>null</code>.
+   * @param message the {@link #getNlsMessage() NLS message} describing the problem briefly.
+   * @param cause the {@link #getCause() cause} of this exception. May be <code>null</code>.
    * @param uuid the explicit {@link #getUuid() UUID} or <code>null</code> to initialize by default (from given
    *        {@link Throwable} or as new {@link UUID}).
    */
@@ -136,18 +136,28 @@ public final UUID getUuid() {
     return this.uuid;
   }
 
+  /**
+   * ATTENTION: Logging frameworks like logback do not follow Java exception standards and write {@link #toString()} but
+   * only {@link #getMessage()} of the {@link Exception} together with the stacktrace into the log. Since an
+   * {@link ApplicationException} contains additional information like {@link #getUuid() UUID} and {@link #getCode()
+   * code} that needs to be logged we are forced to return the message from this method in the following form:
+   *
+   * <pre>[{@link #getCode() «code»}: ]{@link #getNlsMessage() «message»}
+   * «uuid»
+   * </pre>
+   *
+   * Please note that the {@link #getCode() code} is omitted if the {@link #getCode()} method is not overridden and
+   * returning a custom code.<br>
+   * In case you want to get the plain exception message, you therefore need to either call
+   * {@link #getLocalizedMessage()} or use {@link #getNlsMessage()}.
+   *
+   * @return the untranslated message in the form specified above.
+   */
   @Override
   public String getMessage() {
 
     StringBuilder buffer = new StringBuilder();
-    getLocalizedMessage(Locale.ROOT, buffer);
-    buffer.append(System.lineSeparator());
-    buffer.append(this.uuid);
-    String code = getCode();
-    if (!getClass().getSimpleName().equals(code)) {
-      buffer.append(":");
-      buffer.append(code);
-    }
+    toString(Locale.ROOT, buffer, true);
     return buffer.toString();
   }
 
@@ -161,6 +171,12 @@ public Localizable getNlsMessage() {
     return this.message;
   }
 
+  @Override
+  public String getLocalizedMessage() {
+
+    return getLocalizedMessage(Locale.getDefault());
+  }
+
   @Override
   public String getLocalizedMessage(Locale locale) {
 
@@ -196,22 +212,14 @@ private static void printStackTrace(ApplicationException throwable, Locale local
 
     try {
       synchronized (buffer) {
-        buffer.append(throwable.getClass().getName());
-        buffer.append(": ");
-        throwable.getLocalizedMessage(locale, buffer);
-        buffer.append(System.lineSeparator());
-        UUID uuid = throwable.getUuid();
-        if (uuid != null) {
-          buffer.append(uuid.toString());
-          buffer.append(System.lineSeparator());
-        }
+        throwable.toString(locale, buffer);
         StackTraceElement[] trace = throwable.getStackTrace();
         for (int i = 0; i < trace.length; i++) {
           buffer.append("\tat ");
           buffer.append(trace[i].toString());
           buffer.append(System.lineSeparator());
         }
-        for (Throwable suppressed : ((Throwable) throwable).getSuppressed()) {
+        for (Throwable suppressed : throwable.getSuppressed()) {
           buffer.append("Suppressed: ");
           buffer.append(System.lineSeparator());
           printStackTraceCause(suppressed, locale, buffer);
@@ -342,14 +350,21 @@ public String toString(Locale locale) {
    */
   public Appendable toString(Locale locale, Appendable appendable) {
 
+    return toString(locale, appendable, false);
+  }
+
+  private Appendable toString(Locale locale, Appendable appendable, boolean omitClass) {
+
     Appendable buffer = appendable;
     if (buffer == null) {
       buffer = new StringBuilder(32);
     }
     try {
       Class<?> myClass = getClass();
-      buffer.append(myClass.getName());
-      buffer.append(": ");
+      if (!omitClass) {
+        buffer.append(myClass.getName());
+        buffer.append(": ");
+      }
       String code = getCode();
       if (!myClass.getSimpleName().equals(code)) {
         buffer.append(code);
diff --git a/core/src/main/java/io/github/mmm/base/exception/ObjectNotFoundException.java b/core/src/main/java/io/github/mmm/base/exception/ObjectNotFoundException.java
index 89f66a0..be7031f 100644
--- a/core/src/main/java/io/github/mmm/base/exception/ObjectNotFoundException.java
+++ b/core/src/main/java/io/github/mmm/base/exception/ObjectNotFoundException.java
@@ -2,6 +2,8 @@
  * http://www.apache.org/licenses/LICENSE-2.0 */
 package io.github.mmm.base.exception;
 
+import java.util.Collection;
+
 import io.github.mmm.base.i18n.Localizable;
 
 /**
@@ -24,7 +26,7 @@ public class ObjectNotFoundException extends ApplicationException {
   /**
    * The constructor.
    *
-   * @param object is a description (e.g. the classname) of the object that was required but could not be found.
+   * @param object the description (e.g. the classname) of the object that was required but could NOT be found.
    */
   public ObjectNotFoundException(Object object) {
 
@@ -34,8 +36,8 @@ public ObjectNotFoundException(Object object) {
   /**
    * The constructor.
    *
-   * @param object is a description (e.g. the classname) of the object that was required but could not be found.
-   * @param key is the key to the required object.
+   * @param object the description (e.g. the classname) of the object that was required but could NOT be found.
+   * @param key the key to the required object.
    */
   public ObjectNotFoundException(Object object, Object key) {
 
@@ -45,16 +47,30 @@ public ObjectNotFoundException(Object object, Object key) {
   /**
    * The constructor.
    *
-   * @param object is a description (e.g. the classname) of the object that was required but could NOT be found.
-   * @param key is the key to the required object.
-   * @param cause is the {@link #getCause() cause} of this exception.
+   * @param object the description (e.g. the classname) of the object that was required but could NOT be found.
+   * @param key the key to the required object.
+   * @param cause the {@link #getCause() cause} of this exception.
    */
   public ObjectNotFoundException(Object object, Object key, Throwable cause) {
 
-    super(createMessage(object, key), cause);
+    this(object, key, null, cause);
   }
 
-  private static String createMessage(Object object, Object key) {
+  /**
+   * The constructor.
+   *
+   * @param object the description (e.g. the classname) of the object that was required but could NOT be found.
+   * @param key the key to the required object.
+   * @param options the available options (e.g. {@link Collection} of comma separated {@link String} of the available
+   *        keys).
+   * @param cause the {@link #getCause() cause} of this exception.
+   */
+  public ObjectNotFoundException(Object object, Object key, Object options, Throwable cause) {
+
+    super(createMessage(object, key, options), cause);
+  }
+
+  private static String createMessage(Object object, Object key, Object options) {
 
     StringBuilder sb = new StringBuilder("Could not find ");
     sb.append(object);
@@ -64,7 +80,10 @@ private static String createMessage(Object object, Object key) {
       sb.append(key);
       sb.append('\'');
     }
-    sb.append(".");
+    if (options != null) {
+      sb.append(" in ");
+      sb.append(options);
+    }
     return sb.toString();
   }
 
@@ -72,7 +91,7 @@ private static String createMessage(Object object, Object key) {
    * The constructor.
    *
    * @param message the {@link #getNlsMessage() NLS message}.
-   * @param cause is the {@link #getCause() cause} of this exception. May be <code>null</code>.
+   * @param cause the {@link #getCause() cause} of this exception. May be <code>null</code>.
    */
   protected ObjectNotFoundException(Localizable message, Throwable cause) {
 
diff --git a/core/src/test/java/io/github/mmm/base/exception/ApplicationExceptionTest.java b/core/src/test/java/io/github/mmm/base/exception/ApplicationExceptionTest.java
new file mode 100644
index 0000000..433dfc5
--- /dev/null
+++ b/core/src/test/java/io/github/mmm/base/exception/ApplicationExceptionTest.java
@@ -0,0 +1,45 @@
+package io.github.mmm.base.exception;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.Locale;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test of {@link ApplicationException}.
+ */
+public class ApplicationExceptionTest extends Assertions {
+
+  @Test
+  public void testWithCode() {
+
+    // arrange
+    String message = "Something went wrong.";
+    String code = "MagicCode";
+    // act
+    ApplicationException exception = new ApplicationException(message) {
+      @Override
+      public String getCode() {
+
+        return code;
+      }
+    };
+    StringWriter sw = new StringWriter(1024);
+    PrintWriter pw = new PrintWriter(sw);
+    exception.printStackTrace(pw);
+    String stackTrace = sw.toString();
+    // assert
+    assertThat(exception.getLocalizedMessage()).isEqualTo(message);
+    assertThat(exception.getLocalizedMessage(Locale.ROOT)).isEqualTo(message);
+    assertThat(exception.getNlsMessage().getMessage()).isEqualTo(message);
+    String msg = code + ": " + message + System.lineSeparator() + exception.getUuid();
+    assertThat(exception.getMessage()).isEqualTo(msg);
+    String toString = exception.getClass().getName() + ": " + msg;
+    assertThat(exception.toString()).isEqualTo(toString);
+    assertThat(stackTrace).startsWith(toString)
+        .contains("io.github.mmm.base.exception.ApplicationExceptionTest.testWithCode(");
+  }
+
+}
diff --git a/core/src/test/java/io/github/mmm/base/exception/ObjectNotFoundExceptionTest.java b/core/src/test/java/io/github/mmm/base/exception/ObjectNotFoundExceptionTest.java
new file mode 100644
index 0000000..0147918
--- /dev/null
+++ b/core/src/test/java/io/github/mmm/base/exception/ObjectNotFoundExceptionTest.java
@@ -0,0 +1,51 @@
+package io.github.mmm.base.exception;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test of {@link ObjectNotFoundException}.
+ */
+public class ObjectNotFoundExceptionTest extends Assertions {
+
+  @Test
+  public void testSimple() {
+
+    // arrange
+    String name = "io.github.mmm.UndefinedObject";
+    // act
+    ObjectNotFoundException exception = new ObjectNotFoundException(name);
+    // assert
+    assertThat(exception.getLocalizedMessage()).isEqualTo("Could not find " + name);
+  }
+
+  @Test
+  public void testWithKey() {
+
+    // arrange
+    String name = "Entity";
+    String key = "MagicKey";
+    // act
+    ObjectNotFoundException exception = new ObjectNotFoundException(name, key);
+    // assert
+    assertThat(exception.getLocalizedMessage()).isEqualTo("Could not find " + name + " for key '" + key + "'");
+  }
+
+  @Test
+  public void testWithKeyAndOptions() {
+
+    // arrange
+    String name = "Entity";
+    String key = "MagicKey";
+    Collection<String> options = List.of("NormalKey", "Key", "HolyKey");
+    // act
+    ObjectNotFoundException exception = new ObjectNotFoundException(name, key, options, null);
+    // assert
+    assertThat(exception.getLocalizedMessage())
+        .isEqualTo("Could not find " + name + " for key '" + key + "' in [NormalKey, Key, HolyKey]");
+  }
+
+}
diff --git a/metainfo/src/test/java/io/github/mmm/base/metadata/MetaInfoTest.java b/metainfo/src/test/java/io/github/mmm/base/metadata/MetaInfoTest.java
index d5ec47b..7c07c7e 100644
--- a/metainfo/src/test/java/io/github/mmm/base/metadata/MetaInfoTest.java
+++ b/metainfo/src/test/java/io/github/mmm/base/metadata/MetaInfoTest.java
@@ -55,7 +55,7 @@ public void testGetRequired() {
       metaInfo.getRequired("key2");
       failBecauseExceptionWasNotThrown(ObjectNotFoundException.class);
     } catch (ObjectNotFoundException e) {
-      assertThat(e).hasMessageContaining("Could not find MetaInfo-value for key 'key2'.");
+      assertThat(e).hasMessageContaining("Could not find MetaInfo-value for key 'key2'");
     }
   }
 
@@ -167,7 +167,7 @@ public void testWithPrefix() {
       metaInfo.getRequired("key2");
       failBecauseExceptionWasNotThrown(ObjectNotFoundException.class);
     } catch (ObjectNotFoundException e) {
-      assertThat(e.getNlsMessage().getMessage()).isEqualTo("Could not find MetaInfo-value for key 'prefix.key2'.");
+      assertThat(e.getNlsMessage().getMessage()).isEqualTo("Could not find MetaInfo-value for key 'prefix.key2'");
     }
 
     // and act