Index: share/man/man5/make.conf.5
===================================================================
--- share/man/man5/make.conf.5
+++ share/man/man5/make.conf.5
@@ -104,6 +104,13 @@
 .Xr make 1
 or in
 .Xr environ 7 .
+In the case of world and kernel builds is is possible to put these variables
+into
+.Xr src.conf 5
+instead of
+.Nm .
+This way the environment for documentation and ports builds is not polluted
+by unrelated variables.
 .Pp
 The following lists provide a name and short description for each
 variable you can use during the indicated builds.