Fixed #13418 -- Added notes on uniqueness requirements for natural keys. Thanks to hunajakippo for the suggestion, and Ramiro Morales for the draft text.
Fixed #13418 -- Added notes on uniqueness requirements for natural keys. Thanks to hunajakippo for the suggestion, and Ramiro Morales for the draft text.

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%4013146

adieu/django-nonrel,adieu/django-nonrel,adieu/django-nonrel