-communication and if deleted will cause communication between server
-and client to fail. Only the user running gnuserv will be able to
-connect to the socket.
+communication. If the symbol USE_TMPDIR is set at the top of gnuserv.h,
+$TMPDIR, when set, is used instead of /tmp. If that file is deleted,
+or TMPDIR has different values for the server and the client, communication
+between server and client will fail. Only the user running gnuserv will be
+able to connect to the socket.