Doc: add warning in README file for issue on included/

diff --git a/Documentation/included/README b/Documentation/included/README
index 5c46262b203001f51227ae9a5916e6beda7526d2..6252de23999b968460941446216d8ac8a9a82890 100644 (file)
--- a/Documentation/included/README
+++ b/Documentation/included/README
@@ -7,3 +7,7 @@ direction and listed here.
 - simple.ly isn't large, but it's included from
   scm/define-markup-commands.scm and should not be removed.
 
+Do not use @ref{} in files in Documentation/included/;
+cross-references should be made with specific macros such as
+@rcontrib{}, @rextend{}, etc.  See Documentation/macros.itexi for a
+complete list.
\ No newline at end of file