diff --git a/gclc/src/main/java/net/bigeon/gclc/command/ParametrizedCommandData.java b/gclc/src/main/java/net/bigeon/gclc/command/ParametrizedCommandData.java
index 40731f5..61b1421 100644
--- a/gclc/src/main/java/net/bigeon/gclc/command/ParametrizedCommandData.java
+++ b/gclc/src/main/java/net/bigeon/gclc/command/ParametrizedCommandData.java
@@ -85,7 +85,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import net.bigeon.gclc.exception.CommandParsingException;
 import net.bigeon.gclc.exception.InvalidParameterException;
 import net.bigeon.gclc.manager.ConsoleInput;
-import net.bigeon.gclc.utils.EmptyInput;
+import net.bigeon.gclc.manager.EmptyInput;
 
 /** An object to handle standardized command parameters.
  *
diff --git a/gclc/src/main/java/net/bigeon/gclc/exception/CommandParsingException.java b/gclc/src/main/java/net/bigeon/gclc/exception/CommandParsingException.java
index 74a8a1a..d9afeee 100644
--- a/gclc/src/main/java/net/bigeon/gclc/exception/CommandParsingException.java
+++ b/gclc/src/main/java/net/bigeon/gclc/exception/CommandParsingException.java
@@ -74,7 +74,7 @@ package net.bigeon.gclc.exception;
 /** An exception raised during command parsing.
  *
  * @author Emmanuel Bigeon */
-public class CommandParsingException extends Exception {
+public final class CommandParsingException extends Exception {
 
     /** svuid. */
     private static final long serialVersionUID = 1L;
diff --git a/gclc/src/main/java/net/bigeon/gclc/exception/InvalidCommandName.java b/gclc/src/main/java/net/bigeon/gclc/exception/InvalidCommandName.java
index 192ef91..1ffefd3 100644
--- a/gclc/src/main/java/net/bigeon/gclc/exception/InvalidCommandName.java
+++ b/gclc/src/main/java/net/bigeon/gclc/exception/InvalidCommandName.java
@@ -75,7 +75,7 @@ package net.bigeon.gclc.exception;
  * the command is already used.
  *
  * @author Emmanuel BIGEON */
-public class InvalidCommandName extends Exception {
+public final class InvalidCommandName extends Exception {
 
     /** the SVUID. */
     private static final long serialVersionUID = 1L;
diff --git a/gclc/src/main/java/net/bigeon/gclc/exception/InvalidParameterException.java b/gclc/src/main/java/net/bigeon/gclc/exception/InvalidParameterException.java
index d50f2f5..0e38aa3 100644
--- a/gclc/src/main/java/net/bigeon/gclc/exception/InvalidParameterException.java
+++ b/gclc/src/main/java/net/bigeon/gclc/exception/InvalidParameterException.java
@@ -75,7 +75,7 @@ package net.bigeon.gclc.exception;
  * parameter definition.
  *
  * @author Emmanuel Bigeon */
-public class InvalidParameterException extends Exception {
+public final class InvalidParameterException extends RuntimeException {
 
     /** the SVUID. */
     private static final long serialVersionUID = 1L;
diff --git a/gclc/src/main/java/net/bigeon/gclc/utils/EmptyInput.java b/gclc/src/main/java/net/bigeon/gclc/manager/EmptyInput.java
similarity index 95%
rename from gclc/src/main/java/net/bigeon/gclc/utils/EmptyInput.java
rename to gclc/src/main/java/net/bigeon/gclc/manager/EmptyInput.java
index 88e1cb3..0f0fdb3 100644
--- a/gclc/src/main/java/net/bigeon/gclc/utils/EmptyInput.java
+++ b/gclc/src/main/java/net/bigeon/gclc/manager/EmptyInput.java
@@ -36,12 +36,10 @@
  * gclc:net.bigeon.gclc.manager.EmptyInput.java
  * Created on: Nov 13, 2017
  */
-package net.bigeon.gclc.utils;
+package net.bigeon.gclc.manager;
 
 import java.util.function.Supplier;
 
-import net.bigeon.gclc.manager.ConsoleInput;
-
 /*-
  * #%L
  * Generic Command Ligne console
diff --git a/gclc/src/main/java/net/bigeon/gclc/utils/SinkOutput.java b/gclc/src/main/java/net/bigeon/gclc/manager/SinkOutput.java
similarity index 95%
rename from gclc/src/main/java/net/bigeon/gclc/utils/SinkOutput.java
rename to gclc/src/main/java/net/bigeon/gclc/manager/SinkOutput.java
index a739950..832a2e0 100644
--- a/gclc/src/main/java/net/bigeon/gclc/utils/SinkOutput.java
+++ b/gclc/src/main/java/net/bigeon/gclc/manager/SinkOutput.java
@@ -36,9 +36,7 @@
  * gclc:net.bigeon.gclc.manager.SinkOutput.java
  * Created on: Nov 13, 2017
  */
-package net.bigeon.gclc.utils;
-
-import net.bigeon.gclc.manager.ConsoleOutput;
+package net.bigeon.gclc.manager;
 
 /*-
  * #%L
diff --git a/gclc/src/main/java/net/bigeon/gclc/manager/forwarding/package-info.java b/gclc/src/main/java/net/bigeon/gclc/manager/forwarding/package-info.java
new file mode 100644
index 0000000..6ea53bc
--- /dev/null
+++ b/gclc/src/main/java/net/bigeon/gclc/manager/forwarding/package-info.java
@@ -0,0 +1,9 @@
+/**
+ * 
+ */
+/** This package contains the {@link java.lang.Runnable} implementations used to
+ * forward messages to or from console output or input.
+ * 
+ * @author Emmanuel Bigeon */
+package net.bigeon.gclc.manager.forwarding;
+
diff --git a/gclc/src/test/java/net/bigeon/gclc/utils/EmptyInputTest.java b/gclc/src/test/java/net/bigeon/gclc/utils/EmptyInputTest.java
index ca1df9a..d4fab25 100644
--- a/gclc/src/test/java/net/bigeon/gclc/utils/EmptyInputTest.java
+++ b/gclc/src/test/java/net/bigeon/gclc/utils/EmptyInputTest.java
@@ -8,6 +8,7 @@ import java.io.IOException;
 import org.junit.Test;
 
 import net.bigeon.gclc.manager.ConsoleInput;
+import net.bigeon.gclc.manager.EmptyInput;
 import net.bigeon.gclc.tools.ConstantString;
 
 public class EmptyInputTest {
diff --git a/gclc/src/test/java/net/bigeon/gclc/utils/SinkOutputTest.java b/gclc/src/test/java/net/bigeon/gclc/utils/SinkOutputTest.java
index cbbc0b6..a4e1215 100644
--- a/gclc/src/test/java/net/bigeon/gclc/utils/SinkOutputTest.java
+++ b/gclc/src/test/java/net/bigeon/gclc/utils/SinkOutputTest.java
@@ -7,6 +7,7 @@ import java.io.IOException;
 import org.junit.Test;
 
 import net.bigeon.gclc.manager.ConsoleOutput;
+import net.bigeon.gclc.manager.SinkOutput;
 
 public class SinkOutputTest {