#. Go to any partner in **Contacts > Contacts**
#. Try to create two partners with the same ref.

* If you selcted the option 'All partners' you can't create two partners with the same ref.
* If you selcted the option 'Only companies' you can't create two companies with the same ref.
* If you selcted the option 'None' you can create two partners with the same ref.