-# You may want to add an OSTYPE macro to get the location of various
-# support files for your operating system environment.
+# You MUST change the `OSTYPE' macro to specify the operating system
+# on which this will run; this will set the location of various
+# support files for your operating system environment. You MAY
+# create a domain file in ../domain and reference it by adding a
+# `DOMAIN' macro after the `OSTYPE' macro. I recommend that you
+# first copy this to another file name so that new sendmail releases
+# will not trash your changes.