Index: share/man/man8/rc.subr.8
===================================================================
--- share/man/man8/rc.subr.8
+++ share/man/man8/rc.subr.8
@@ -29,7 +29,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd July 31, 2020
+.Dd May 18, 2021
 .Dt RC.SUBR 8
 .Os
 .Sh NAME
@@ -780,6 +780,19 @@
 .Dq Li NO .
 .El
 .Pp
+Note that when a
+.Ao Ar name Ac Ns Va _variable
+is defined, if the default method provided by the
+.Ic run_rc_command ,
+method is overridden, the functionality will silently fail.
+This means that
+.Ao Ar name Ac Ns Va _oomprotect ,
+and
+.Ao Ar name Ac Ns Va _nice ,
+and
+.Ao Ar name Ac Ns Va _limits
+and similar variables will not function for rc scripts that override _start.
+.Pp
 The following variables are available to the methods
 (such as
 .Ar argument Ns Va _cmd )