diff --git a/templates/file_list.html b/templates/file_list.html
index 65aa261..1cf5151 100644
--- a/templates/file_list.html
+++ b/templates/file_list.html
@@ -40,6 +40,8 @@
     // this is the list of entry ids for the images for ALL matches for this query
     var entryList={{query_data.entry_list}}
     var OPT = {{ OPT.to_dict()|tojson }};
+    // set from query data and stored in OPT for convenience.  It can be 0 -
+    // this implies no content in the Path at all
     OPT.root_eid = {{ query_data.root_eid }};
 
     // pageList is just those entries shown on this page from the full entryList
diff --git a/templates/files.html b/templates/files.html
index eb91c2f..adb087f 100644
--- a/templates/files.html
+++ b/templates/files.html
@@ -247,6 +247,8 @@
     document.viewing=null;
 
     var OPT = {{ OPT.to_dict()|tojson }};
+    // set from query data and stored in OPT for convenience.  It can be 0 -
+    // this implies no content in the Path at all
     OPT.root_eid = {{ query_data.root_eid }};
 
     // get items out of query_data into convenience javascript vars...