Index: head/tools/build/options/WITH_META_MODE
===================================================================
--- head/tools/build/options/WITH_META_MODE	(revision 287972)
+++ head/tools/build/options/WITH_META_MODE	(revision 287973)
@@ -1,31 +1,37 @@
 .\" $FreeBSD$
 Enable building in meta mode.
+This is an experimental build feature.
+For details see
+http://www.crufty.net/sjg/docs/freebsd-meta-mode.htm.
 .Pp
 The build is driven by dirdeps.mk using
 .Va DIRDEPS
 stored in
 Makefile.depend files found in each directory.
 .Pp
 The build can be started from anywhere, and behaves the same.
 The initial instance of
 .Xr make 1 
 recursively reads
 .Va DIRDEPS
 from Makefile.depend
 computing a graph of tree dependencies from the current origin.
-See http://www.crufty.net/help/sjg/dirdeps.htm
+Setting
+.Va NO_DIRDEPS
+will skip checking dirdep dependencies and will only build in the current
+directory.
 .Pp
 As each target is made
 .Xr make 1
 produces a meta file which is used to capture (and compare)
 the command line,
 as well as any command output.
 If
 .Xr filemon 4
 is available the meta file will also capture a record of files
 used to produce the target by tracking syscalls.
 .Pp
 The build will hide commands ran unless
 .Va NO_SILENT
 is defined.
 .Pp