diff --git a/azure-mgmt-resource/azure/mgmt/resource/resources/v2018_05_01/operations/resource_groups_operations.py b/azure-mgmt-resource/azure/mgmt/resource/resources/v2018_05_01/operations/resource_groups_operations.py
index a454763e818d..1bfec99bf6d3 100644
--- a/azure-mgmt-resource/azure/mgmt/resource/resources/v2018_05_01/operations/resource_groups_operations.py
+++ b/azure-mgmt-resource/azure/mgmt/resource/resources/v2018_05_01/operations/resource_groups_operations.py
@@ -97,7 +97,9 @@ def create_or_update(
         """Creates or updates a resource group.
 
         :param resource_group_name: The name of the resource group to create
-         or update.
+         or update. Can include alphanumeric, underscore, parentheses, hyphen,
+         period (except at end), and Unicode characters that match the allowed
+         characters.
         :type resource_group_name: str
         :param parameters: Parameters supplied to the create or update a
          resource group.