diff --git a/README.rst b/README.rst
index 73038cd..a222533 100644
--- a/README.rst
+++ b/README.rst
@@ -157,8 +157,8 @@ will be import into Python as a dictionary.
 
 * The schedule is a list of dictionaries each consisting of `time` in UTC,
   `day` of the week, the `irc` meeting room, and the `frequency` of the
-  meeting. Options for the `frequency` are `weekly`, `biweekly-even`, and
-  `biweekly-odd` at the moment.
+  meeting. Options for the `frequency` are `weekly`, `biweekly-even`,
+  `biweekly-odd`, and `adhoc` at the moment.
 
   `biweekly-odd` are weeks where the ISO week number is an odd value.
   Correspondingly `biweekly-even` are weeks where the ISO week number is even.
@@ -166,6 +166,10 @@ will be import into Python as a dictionary.
   2015 has 53 ISO weeks (an odd value) and then the first week of 2016 is week
   1 (also an odd value).
 
+  `adhoc` can be used to list the possibility of something in the schedule but
+  will not actually generate any calendar events. This can be used for
+  placeholders and will act as a noop when generating the calendar.
+
   ::
 
     schedule: