-Bison can work with pre-1.4.3 distributions of GNU m4 if they are
-sufficiently patched, but if you encounter a bug with an older
-distribution and report a bug we will probably suggest that you
-upgrade to 1.4.3 as the first step in trying to fix it.
+** Internationalization
+Bison supports two catalogues: one for Bison itself (i.e., for the
+maintainer-side parser generation), and one for the generated parsers
+(i.e., for the user-side parser execution). The requirements between
+both differ: bison needs ngettext, the generated parsers do not. To
+simplify the build system, neither are installed if ngettext is not
+supported, even if generated parsers could have been localized. See
+http://lists.gnu.org/archive/html/bug-bison/2009-08/msg00006.html for
+more details.