diff --git a/docs/ref/contrib/auth.txt b/docs/ref/contrib/auth.txt
index 402496a2db..b50bc966e5 100644
--- a/docs/ref/contrib/auth.txt
+++ b/docs/ref/contrib/auth.txt
@@ -47,15 +47,18 @@ Fields
 
     .. attribute:: first_name
 
-        Optional. 30 characters or fewer.
+        Optional (:attr:`blank=True <django.db.models.Field.blank>`). 30
+        characters or fewer.
 
     .. attribute:: last_name
 
-        Optional. 30 characters or fewer.
+        Optional (:attr:`blank=True <django.db.models.Field.blank>`). 30
+        characters or fewer.
 
     .. attribute:: email
 
-        Optional. Email address.
+        Optional (:attr:`blank=True <django.db.models.Field.blank>`). Email
+        address.
 
     .. attribute:: password