--- a/qrurls/models.py	Sun Aug 18 23:12:54 2013 +0300
+++ b/qrurls/models.py	Sun Aug 18 23:24:54 2013 +0300
@@ -42,7 +42,8 @@
         return super(SecretFileSystemStorage, self).save(name, content)
 
 class URL(models.Model):
-    shorturl = models.SlugField(unique=True)
+    shorturl = models.SlugField(unique=True,
+            help_text="Changing this will break existing QR-codes!")
     publishing_time = models.TimeField(default=datetime.time(),
             help_text="Default time to publish new URLItems (in timezone)")