-# a 1x1 transparent GIF. And finally, "+image-blocker{http://xyz.com}"
-# will send a HTTP temporary redirect to the specified image - this
-# has the advantage of the icon being beeing cached by the browser,
-# which will speed up the display.
+# a 1x1 transparent PNG, "+image-blocker{pattern}" will send a 4x4
+# grey/white pattern which is less intrusive than the logo but easier
+# to recognize than the transparent one. And finally, "+image-blocker{<URL>}"
+# will send a HTTP temporary redirect to the specified image URL.