[1.7.x] Refs #23964 -- Added warning about case-insensitive, unique fields used with formsets

Backport of 4d27d72d149b714431b77f2f15bad1591a9602b7 from master

1 files changed, 7 insertions, 0 deletions

diff --git a/docs/ref/databases.txt b/docs/ref/databases.txt
index b0396dea08..24e593569e 100644
--- a/docs/ref/databases.txt
+++ b/docs/ref/databases.txt
@@ -408,6 +408,13 @@ because it is more accurate.
 
 .. _MySQL Unicode Character Sets: http://dev.mysql.com/doc/refman/5.7/en/charset-unicode-sets.html
 
+.. warning::
+
+    Model formsets validate unique fields in a case-sensitive manner. Thus when
+    using a case-insensitive collation, a formset with unique field values that
+    differ only by case will pass validation, but upon calling ``save()``, an
+    ``IntegrityError`` will be raised.
+
 Connecting to the database
 --------------------------