-BASE_DIR, MYSQL_DB, MYSQL_HOST, MYSQL_PASS, MYSQL_USER, WEBSERVER_DOMAIN,
-WEBSERVER_HOST, WEBSERVER_IP, ZEBRA_PASS, ZEBRA_USER
+PREFIX,
+BASE_DIR, CGI_DIR, LOG_DIR,
+DB_TYPE, DB_HOST, DB_PORT, DB_NAME, DB_PASS, DB_USER, WEBMASTER_EMAIL, WEBSERVER_DOMAIN,
+WEBSERVER_HOST, WEBSERVER_IP, WEBSERVER_PORT, WEBSERVER_PORT_LIBRARIAN, ZEBRA_PASS, ZEBRA_USER
+
+=head1 EXAMPLES
+
+To override the guessed hostname and email address, run:
+
+ WEBSERVER_HOST=mysecrethostname.com.invalid \
+ WEBMASTER_EMAIL=webmaster@publichost.com make install
+
+Note that if WEBSERVER_HOST does not resolve to an IP address, you will
+also need to override WEBSERVER_IP.