diff --git a/html/rest.html b/html/rest.html
index 7fb2887a5fbd78ab80a2502da694b05e2698add5..0611c1ec7cabb881a74b8f4c4cfd458e2fc07515 100644
--- a/html/rest.html
+++ b/html/rest.html
@@ -12,7 +12,7 @@
 <h2>REST interface</h2>
 <p>
 The Alignment server provides a REST interface for accessing the
-functions available on the server. Each request is an URL starting
+functions available on the server (when launched with the -W switch). Each request is an URL starting
 with a prefix, e.g., http://aserv.inrialpes.fr/rest/. The request type
 is identified by a string followed by a question mark, e.g., match?,
 and parameters are given in the classical URL syntax, e.g.,