diff --git a/README.md b/README.md
index fd82560..5c8aeb6 100644
--- a/README.md
+++ b/README.md
@@ -127,6 +127,18 @@ Bulk invites are supported via JSON.  Post a list of comma separated emails to t
 
     App registry path of the invitation model used in the current project, for customization purposes.
 
+*  `INVITE_FORM` (default=`invitations.forms.InviteForm`)
+
+    Form class used for sending invites outside admin.
+
+*  `ADMIN_ADD_FORM` (default=`invitations.forms.InvitationAdminAddForm`)
+
+    Form class used for sending invites in admin.
+
+*  `ADMIN_CHANGE_FORM` (default=`invitations.forms.InvitationAdminChangeForm`)
+
+    Form class used for updating invitations in admin.
+
 ### Signals
 
 The following signals are emitted:
diff --git a/invitations/app_settings.py b/invitations/app_settings.py
index d2b59d1..bc23ad7 100644
--- a/invitations/app_settings.py
+++ b/invitations/app_settings.py
@@ -6,9 +6,8 @@ class AppSettings(object):
     def __init__(self, prefix):
         self.prefix = prefix
 
-    def _setting(self, name, dflt):
-        from django.conf import settings
-        return getattr(settings, self.prefix + name, dflt)
+    def _setting(self, name, default):
+        return getattr(settings, self.prefix + name, default)
 
     @property
     def INVITATION_EXPIRY(self):
@@ -82,10 +81,16 @@ def INVITATION_MODEL(self):
 
     @property
     def INVITE_FORM(self):
+        """
+        Form class used for sending invites outside admin.
+        """
         return self._setting("INVITE_FORM", "invitations.forms.InviteForm")
 
     @property
     def ADMIN_ADD_FORM(self):
+        """
+        Form class used for sending invites in admin.
+        """
         return self._setting(
             "ADMIN_ADD_FORM",
             "invitations.forms.InvitationAdminAddForm"
@@ -93,6 +98,9 @@ def ADMIN_ADD_FORM(self):
 
     @property
     def ADMIN_CHANGE_FORM(self):
+        """
+        Form class used for updating invitations in admin.
+        """
         return self._setting(
             "ADMIN_CHANGE_FORM",
             "invitations.forms.InvitationAdminChangeForm"
diff --git a/invitations/utils.py b/invitations/utils.py
index f966614..f8c2c7b 100644
--- a/invitations/utils.py
+++ b/invitations/utils.py
@@ -18,14 +18,23 @@ def import_attribute(path):
 
 
 def get_invite_form():
+    """
+    Returns the form for sending an invite.
+    """
     return import_attribute(app_settings.INVITE_FORM)
 
 
 def get_invitation_admin_add_form():
+    """
+    Returns the form for creating a new invitation in admin.
+    """
     return import_attribute(app_settings.ADMIN_ADD_FORM)
 
 
 def get_invitation_admin_change_form():
+    """
+    Returns the form for changing invitations in admin.
+    """
     return import_attribute(app_settings.ADMIN_CHANGE_FORM)