diff --git a/Input/InputOption.php b/Input/InputOption.php
index a8e956db5..5e48f88b8 100644
--- a/Input/InputOption.php
+++ b/Input/InputOption.php
@@ -21,9 +21,24 @@
  */
 class InputOption
 {
+    /**
+     * Do not accept input for the option (e.g. --yell). This is the default behavior of options.
+     */
     public const VALUE_NONE = 1;
+
+    /**
+     * A value must be passed when the option is used (e.g. --iterations=5 or -i5).
+     */
     public const VALUE_REQUIRED = 2;
+
+    /**
+     * The option may or may not have a value (e.g. --yell or --yell=loud).
+     */
     public const VALUE_OPTIONAL = 4;
+
+    /**
+     * The option accepts multiple values (e.g. --dir=/foo --dir=/bar).
+     */
     public const VALUE_IS_ARRAY = 8;
 
     private $name;