--- a/src/README
+++ b/src/README
@@ -330,6 +330,10 @@
    Example: "user manual" will look only for occurrences of user immediately
    followed by manual. You can use the This exact phrase field of the
    advanced search dialog to the same effect.
+
+   Query explanation. You can get an exact description of what the query
+   looked for, including stem expansion, and boolean operators used, by
+   clicking on the result list header.
 
    Quitting. Entering ^Q almost anywhere will close the application.