diff --git a/docs/naming_convention.rst b/docs/naming_convention.rst
index 17259536b..2d1233b83 100644
--- a/docs/naming_convention.rst
+++ b/docs/naming_convention.rst
@@ -70,3 +70,5 @@ The regular expression that validates our variable and family naming policy is:
 
 You can see that it is mandatory to only use lowercase ASCII letters, numbers and the `"_"` (undescore) character. 
 The snake case typographic convention is therefore used.
+
+.. attention:: The name must not starts with `_` character.