documentation (commiting now from Guadeloupe)

Visitor/RoleVisitor.php

@@ -5,13 +5,19 @@ namespace DesignPatterns\Visitor;
 /**
  * Visitor Pattern
  *
- * The contract for the visitor
+ * The contract for the visitor.
+ * 
+ * Note 1 : in C++ or java, with method polymorphism based on type-hint, there are many
+ * methods visit() with different type for the 'role' parameter.
+ * 
+ * Note 2 : the visitor must not choose itself which method to
+ * invoke, it is the Visitee that make this decision.
  */
 interface RoleVisitor
 {
 
     /**
-     * Visit a user object
+     * Visit a User object
      * 
      * @param \DesignPatterns\Visitor\User $role
      */