Index: usr.bin/fortune/datfiles/freebsd-tips
===================================================================
--- usr.bin/fortune/datfiles/freebsd-tips
+++ usr.bin/fortune/datfiles/freebsd-tips
@@ -836,3 +836,10 @@
 
 		-- Daniel Ebdrup Jensen <debdrup@FreeBSD.org>
 %
+You can enable kernel stack(9) traces on ^T (tty info) by changing
+kern.tty_info_kstacks to 1 (on) or 2 (verbose):
+
+$ sysctl kern.tty_info_kstacks=2
+
+		-- Michael Gmelin <grembo@FreeBSD.org>
+%