diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 6642e3a08..707c6127e 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -320,6 +320,8 @@ the database::
 Implementing PXE Filter Drivers
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+.. note:: It is not possible yet to use PXE filter drivers.
+
 Background
 ----------
 
diff --git a/example.conf b/example.conf
index 946e5f1b1..62335f998 100644
--- a/example.conf
+++ b/example.conf
@@ -761,11 +761,12 @@
 # From ironic_inspector
 #
 
-# PXE boot filter driver to use, such as iptables (string value)
+# PXE boot filter driver to use, such as iptables. This option has no
+# effect yet. (string value)
 #driver = noop
 
 # Amount of time in seconds, after which repeat periodic update of the
-# filter. (integer value)
+# filter. This option has no effect yet. (integer value)
 # Minimum value: 0
 #sync_period = 15
 
diff --git a/ironic_inspector/conf.py b/ironic_inspector/conf.py
index b043e9e66..57b855f29 100644
--- a/ironic_inspector/conf.py
+++ b/ironic_inspector/conf.py
@@ -190,10 +190,11 @@ SERVICE_OPTS = [
 
 PXE_FILTER_OPTS = [
     cfg.StrOpt('driver', default='noop',
-               help=_('PXE boot filter driver to use, such as iptables')),
+               help=_('PXE boot filter driver to use, such as iptables. '
+                      'This option has no effect yet.')),
     cfg.IntOpt('sync_period', default=15, min=0,
                help=_('Amount of time in seconds, after which repeat periodic '
-                      'update of the filter.')),
+                      'update of the filter. This option has no effect yet.')),
 ]
 
 cfg.CONF.register_opts(SERVICE_OPTS)