--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-01-15  Bruno Haible  <bruno@clisp.org>
+
+	* doc/gnulib-intro.texi (Copyright): Explain the different license
+	terms for module descriptions, autoconf macros, tests, documentation.
+
 2007-01-14  Bruno Haible  <bruno@clisp.org>
 
 	* modules/striconv-tests: New file.

--- a/doc/gnulib-intro.texi
+++ b/doc/gnulib-intro.texi
@@ -214,6 +214,49 @@
 always say "GPL", but the real license specification is in the module
 description file.
 
+More precisely, the license specification is in the module description
+file applies to the files in @file{lib/} and @file{build-aux/}.  Different
+licenses apply to files in special directories:
+
+@table @file
+@item modules/
+Module description files are under this copyright:
+
+@quotation
+Copyright @copyright{} 2002-2007 Free Software Foundation, Inc.@*
+Copying and distribution of this file, with or without modification,
+in any medium, are permitted without royalty provided the copyright
+notice and this notice are preserved.
+@end quotation
+
+@item m4/
+Autoconf macro files are under this copyright:
+
+@quotation
+Copyright @copyright{} 2002-2007 Free Software Foundation, Inc.@*
+This file is free software; the Free Software Foundation
+gives unlimited permission to copy and/or distribute it,
+with or without modifications, as long as this notice is preserved.
+@end quotation
+
+@item tests/
+If a license statement is not present in a test module, the test files are
+under GPL.  Even if the corresponding source module is under LGPL, this is
+not a problem, since compiled tests are not installed by ``make install''.
+
+@item doc/
+Documentation files are under this copyright:
+
+@quotation
+Copyright @copyright{} 2002-2007 Free Software Foundation, Inc.@*
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.1 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts.
+@end quotation
+@end table
+
 If you want to use some Gnulib modules under LGPL, you can do so by
 passing the option @samp{--lgpl} to @code{gnulib-tool}.  This will
 replace the GPL header with an LGPL header while copying the source