--- /dev/null
+If you want to indent this source file, in order to convert
+the source tree to the used programming style, you should use
+`make indent' in the base directory.
+
+For this to work you need to have `indent' version 2.1.0 or higher
+in your PATH. GNU indent 2.1.0 is available from all GNU sites,
+its main ftp site is ftp://ftp.gnu.org/indent/. Or you can download
+it directly from the webpage of its maintainer at
+http://www.xs4all.nl/~carlo17/indent/