diff --git a/scribblings/cs019.scrbl b/scribblings/cs019.scrbl
index 8559076..5c18f50 100644
--- a/scribblings/cs019.scrbl
+++ b/scribblings/cs019.scrbl
@@ -890,6 +890,28 @@ even if the id does not currently exist on the page.
 }
 
 
+@subsection{Shrink final versions of programs}
+The JavaScript files generated by Whalesong can be compressed by using
+ the @tt{@"-"}@tt{@"-"compress@"-"javascript} option during @tt{build}.
+
+For example:
+@verbatim|{
+$ whalesong build pacman.rkt
+[omitting output]
+
+$ ls -l pacman.js
+-rw-rw-r-- 1 dyoo nogroup 1181979 Nov  9 15:19 pacman.js
+
+$ whalesong build --compress-javascript pacman.rkt
+[omitting output]
+$ ls -l pacman.js
+-rw-rw-r-- 1 dyoo nogroup 782199 Nov  9 15:19 pacman.js
+}|
+
+Compression takes some time, so it is not turned on by default.  It
+may be useful when deploying a finished program.
+
+
 
 @section{Known bugs and deviations}