Uniqueness constraints imply a forced 'required=True'. Refs #1945

1 files changed, 10 insertions, 0 deletions

diff --git a/docs/api-guide/validators.md b/docs/api-guide/validators.md
index 6a0ef4ff..bb073f57 100644
--- a/docs/api-guide/validators.md
+++ b/docs/api-guide/validators.md
@@ -93,6 +93,12 @@ The validator should be applied to *serializer classes*, like so:
                 )
             ]
 
+---
+
+**Note**: The `UniqueTogetherValidation` class always imposes an implicit constraint that all the fields it applies to are always treated as required. Fields with `default` values are an exception to this as they always supply a value even when omitted from user input.
+
+---
+
 ## UniqueForDateValidator
 
 ## UniqueForMonthValidator
@@ -146,6 +152,10 @@ If you want the date field to be entirely hidden from the user, then use `Hidden
 
 ---
 
+**Note**: The `UniqueFor<Range>Validation` classes always imposes an implicit constraint that the fields they are applied to are always treated as required. Fields with `default` values are an exception to this as they always supply a value even when omitted from user input.
+
+---
+
 # Writing custom validators
 
 You can use any of Django's existing validators, or write your own custom validators.