diff --git a/crossfire/logging.rkt b/crossfire/logging.rkt
index 3fdd90c..1f2c494 100644
--- a/crossfire/logging.rkt
+++ b/crossfire/logging.rkt
@@ -78,6 +78,7 @@
     (make-log-receiver
       global-logger
       ;; set of default filters
+      ;; https://groups.google.com/g/racket-users/c/Nl4DNKUI2tk/m/Qzt58ib9BAAJ
       'info    'optimizer
       'warning 'collapsible-contract-bailout
       'warning 'collapsible-value-bailout