diff --git a/lib/libutil/login.conf.5 b/lib/libutil/login.conf.5
--- a/lib/libutil/login.conf.5
+++ b/lib/libutil/login.conf.5
@@ -255,7 +255,9 @@
 from other means.
 .It "timezone	string		Default value of $TZ environment variable."
 .It "umask	number		Initial umask. Should always have a leading 0 to"
-ensure octal interpretation.
+ensure octal interpretation.  Special value
+.Ql inherit
+explicitly indicates not to change the umask.
 .It "welcome	file	/etc/motd	File containing welcome message."
 .El
 .Sh AUTHENTICATION