diff --git a/inc/caldav-LOCK.php b/inc/caldav-LOCK.php
new file mode 100644
index 00000000..d5216a1b
--- /dev/null
+++ b/inc/caldav-LOCK.php
@@ -0,0 +1,11 @@
+<?php
+/**
+* We support both LOCK and UNLOCK methods in this function
+*/
+
+  echo "<h1>Unimplemented</h1><p>Unfortunately this function is planned, but not yet implemented</p";
+  echo "<p>Well, actually, perhaps 'planned' is too strong a word.  It <em>is</em> on the roadmap, and if you want to
+contribute to the planning, please add your two cents to the Sourceforge forums or tracker items.</p>";
+  echo "<p>It would also be useful if you could find a client which uses it, maybe even a log of it
+doing so, and so on.</p>";
+?>
\ No newline at end of file