diff --git a/static/index.html b/static/index.html
index db07feb29..c8e644a4f 100644
--- a/static/index.html
+++ b/static/index.html
@@ -202,6 +202,10 @@
           Use the above filters to include and exclude words or characters
           (separated by spaces)
         </div>
+        <div class="tip">
+          "Set" replaces the current selection with the selected language,
+          "Add" appends the selected language to the current selection
+        </div>
         <i
           class="fas fa-fw fa-spin fa-circle-notch hidden loadingIndicator"
         ></i>