diff --git a/sic.1 b/sic.1
index 35f2b92..2d453d3 100644
--- a/sic.1
+++ b/sic.1
@@ -29,3 +29,9 @@ set the channel topic
 .TP
 Everything which is not a command will simply be posted into the channel or to
 the server.
+.SH CUSTOMIZATION
+.B sic
+is customized through editing its source code.  This keeps it fast, secure and
+simple. The source code contains the
+.I CUSTOMIZE
+keyword to highlight relevant portions for customization.