diff --git a/DnsServerCore/www/index.html b/DnsServerCore/www/index.html
index d96193f9..1770ee6e 100644
--- a/DnsServerCore/www/index.html
+++ b/DnsServerCore/www/index.html
@@ -1037,8 +1037,10 @@
 
                                                             <option value="https://dbl.oisd.nl/">OISD Block List by sjhgvr (https://dbl.oisd.nl/)</option>
                                                         </select>
-
-                                                        <div style="margin-top: 10px;">Enter block list URL one below another in the above text field or use the Quick Add list to add known block list URLs.</div>
+                                                    </div>
+                                                    <div class="col-sm-offset-3 col-sm-8" style="padding-top: 5px;">
+                                                        <p>Enter block list URL one below another in the above text field or use the Quick Add list to add known block list URLs.</p>
+                                                        <p>Add <code>!</code> character at the start of an URL to make it an allow list URL. Domain names in such an allow list URL are prevented from being added to the block list zone.</p>
                                                     </div>
                                                 </div>