+@node References
+@chapter References to Non-Free Software and Documentation
+@cindex references to non-free material
+
+A GNU program should not recommend use of any non-free program. We
+can't stop some people from writing proprietary programs, or stop
+other people from using them, but we can and should avoid helping to
+advertise them to new potential customers. Proprietary software is a
+social and ethical problem, and the point of GNU is to solve that
+problem.
+
+When a non-free program or system is well known, you can mention it in
+passing---that is harmless, since users who might want to use it
+probably already know about it. For instance, it is fine to explain
+how to build your package on top of some non-free operating system, or
+how to use it together with some widely used non-free program.
+
+However, you should give only the necessary information to help those
+who already use the non-free program to use your program with
+it---don't give, or refer to, any further information about the
+proprietary program, and don't imply that the proprietary program
+enhances your program, or that its existence is in any way a good
+thing. The goal should be that people already using the proprietary
+program will get the advice they need about how to use your free
+program, while people who don't already use the proprietary program
+will not see anything to lead them to take an interest in it.
+
+If a non-free program or system is obscure in your program's domain,
+your program should not mention or support it at all, since doing so
+would tend to popularize the non-free program more than it popularizes
+your program. (You cannot hope to find many additional users among
+the users of Foobar if the users of Foobar are few.)
+
+A GNU package should not refer the user to any non-free documentation
+for free software. Free documentation that can be included in free
+operating systems is essential for completing the GNU system, so it is
+a major focus of the GNU Project; to recommend use of documentation
+that we are not allowed to use in GNU would undermine the efforts to
+get documentation that we can include. So GNU packages should never
+recommend non-free documentation.
+
+@node Copying This Manual
+@appendix Copying This Manual
+
+@menu
+* GNU Free Documentation License:: License for copying this manual
+@end menu
+
+@include fdl.texi
+
+@node Index
+@unnumbered Index
+@printindex cp
+