diff --git a/etc/refcards/README b/etc/refcards/README
index 78ace90c934..a8dfc839302 100644
--- a/etc/refcards/README
+++ b/etc/refcards/README
@@ -1,3 +1,10 @@
+Some of the *.tex files need special versions of TeX to typeset them.
+The files cs-*.tex and sk-*.tex need csTeX, a special version of TeX
+tailored to typesetting Czech and Slovak documents.  We provide
+generated files for these documents, so that you could print them
+without installing the modified TeX versions.
+
+
 COPYRIGHT AND LICENSE INFORMATION FOR IMAGE FILES
 
 The file gnus-logo.eps contains contain copyright and license