diff --git a/2020/otterness/index.html b/2020/otterness/index.html
index bce40cad3..18ae09dfc 100644
--- a/2020/otterness/index.html
+++ b/2020/otterness/index.html
@@ -486,6 +486,10 @@ especially true for “live performance” .mid files.</p></li>
 correctly parse, but I have rarely seen this in practice. The largest
 cause of program failures, in my experience, has been Limitation 2.</p></li>
 </ol>
+<h3 id="notice-to-those-who-wish-for-a-greater-challenge-1">NOTICE to those who wish for a greater challenge:</h3>
+<p><strong>If you want a greater challenge, don’t read any further</strong>:
+just try to understand the program via the source.</p>
+<p>If you get stuck, come back and read below for additional hints and information.</p>
 <h4 id="obfuscation-notes">Obfuscation notes</h4>
 <p>I had one primary goal when writing this program: include no C literals
 whatsoever. The final C file includes no numerical, string, or character