diff --git a/passbook/saml_idp/forms.py b/passbook/saml_idp/forms.py
index 98a17cc32..6f04d5344 100644
--- a/passbook/saml_idp/forms.py
+++ b/passbook/saml_idp/forms.py
@@ -54,3 +54,6 @@ class SAMLPropertyMappingForm(forms.ModelForm):
         field_classes = {
             'values': DynamicArrayField
         }
+        help_texts = {
+            'values': 'String substitution uses a syntax like "{variable} test}".'
+        }