diff --git a/public_html/config.js b/public_html/config.js
index 8b34bc2..5a134e3 100644
--- a/public_html/config.js
+++ b/public_html/config.js
@@ -118,3 +118,8 @@ ChartBundleLayers = false;
 //   BingMapsAPIKey = "your key here";
 //
 BingMapsAPIKey = null;
+
+// Turn on display of extra Mode S EHS / ADS-B v1/v2 data
+// This is not polished yet (and so is disabled by default),
+// currently it's just a data dump of the new fields with no UX work.
+ExtendedData = false;
diff --git a/public_html/index.html b/public_html/index.html
index ba582ce..dd25799 100644
--- a/public_html/index.html
+++ b/public_html/index.html
@@ -172,6 +172,7 @@
 					</div>
 
 
+                                      <div id="extendedData" class="hidden">
 					<div class="infoBlockSection lightGreyBackground">
 					  <div>
                                             <div class="infoHeading infoRowFluid fourColumnSection1">Alt (geom):</div>
@@ -229,6 +230,7 @@
                                             <div class="infoData infoRowFluid fourColumnSection2"><span id="selected_version"/></div>
                                           </div>
 				        </div>
+                                      </div>
 
                                         <a href="http://www.airframes.org/" onclick="document.getElementById('horrible_hack').submit.call(document.getElementById('airframes_post')); return false;" class="link rightLink">
 						AirFrames.org
diff --git a/public_html/script.js b/public_html/script.js
index 4afbbea..43be896 100644
--- a/public_html/script.js
+++ b/public_html/script.js
@@ -197,7 +197,11 @@ function initialize() {
         refreshClock();
 
         $("#loader").removeClass("hidden");
-        
+
+        if (ExtendedData) {
+                $("#extendedData").removeClass("hidden");
+        }
+
         // Set up map/sidebar splitter
         $("#sidebar_container").resizable({handles: {w: '#splitter'}});