Dears,

I want to create a custom field, type "Pick List", to define the language of a Lead.

I want a pick list with some options value ("en", "fr", "de", etc.) and I want to display this options with a reference ("English" for "en", "Français" for "fr", etc.). 
I know that I should use Reference Values for this, but in my case I cannot find the link to that :

Can someone help me?