diff --git a/app/assets/javascripts/src/Metamaps.js.erb b/app/assets/javascripts/src/Metamaps.js.erb
index d315f733..5a6c5955 100644
--- a/app/assets/javascripts/src/Metamaps.js.erb
+++ b/app/assets/javascripts/src/Metamaps.js.erb
@@ -1,3 +1,5 @@
+// TODO document this user agent function
+
 var labelType, useGradients, nativeTextSupport, animate;
 
 (function () {