diff --git a/Appendix-C:-Test-Sites.md b/Appendix-C:-Test-Sites.md
index b38300d..534070b 100644
--- a/Appendix-C:-Test-Sites.md
+++ b/Appendix-C:-Test-Sites.md
@@ -64,7 +64,7 @@ If you would like to submit a test page to be added to this list, please post th
 
 [1] Since Firefox 52, the Battery Status API is now chrome/privileged access and is not accessible by web pages.
 
-[2] This test is a PoC (proof of concept). You will need `layout.css.visited_links_enabled` set as `true`. You will also need a normal window (not a Private Browsing one). The PoC only covers a handful of sites, and many of those will not show as they have moved to HTTPS. For best results:
+[2] This test is a PoC (proof of concept). You will need `layout.css.visited_links_enabled` set as `true`. You will also need a normal window (not a Private Browsing one). The PoC only covers a handful of sites, and many of those will not "leak" as the code is checking HTTP and the site has moved to HTTPS - i.e the full URL has changed. For best results:
  * Open a normal window in a vanilla Firefox. Clear everything (Ctrl-Shift-Del).
  * Go to http://www.cnn.com/ and http://www.foxnews.com/
  * Go to the [test page](http://lcamtuf.coredump.cx/yahh/) and play a game (takes 30 seconds or so)