diff --git a/Docs/Dev/img/er.png b/Docs/Dev/img/er.png
new file mode 100644
index 0000000..ce0e2b9
Binary files /dev/null and b/Docs/Dev/img/er.png differ
diff --git a/Models/AttributeValueType.php b/Models/AttributeValueType.php
index 7bd1a09..6c1c4af 100755
--- a/Models/AttributeValueType.php
+++ b/Models/AttributeValueType.php
@@ -26,11 +26,11 @@ use phpOMS\Stdlib\Base\Enum;
  */
 abstract class AttributeValueType extends Enum
 {
-    public const _INT = 0;
+    public const _INT = 1;
 
-    public const _STRING = 1;
+    public const _STRING = 2;
 
-    public const _FLOAT = 2;
+    public const _FLOAT = 3;
 
-    public const _DATETIME = 3;
+    public const _DATETIME = 4;
 }