disallow multiple input FLAC files when --import-tags-from=- is used (SF#1082577 http://sourceforge.net/tracker/index.php?func=detail&aid=1082577&group_id=13478&atid=113478)
diff --git a/man/metaflac.sgml b/man/metaflac.sgml
index 3a80a37..90697a9 100644
--- a/man/metaflac.sgml
+++ b/man/metaflac.sgml
@@ -265,7 +265,8 @@
 	    Import tags from a file.  Use '-' for stdin.  Each
 	    line should be of the form NAME=VALUE.  Multi-line comments
 	    are currently not supported.  Specify --remove-all-tags and/or
-	    --no-utf8-convert before --import-tags-from if necessary.
+	    --no-utf8-convert before --import-tags-from if necessary.  If
+	    FILE is '-' (stdin), only one FLAC file may be specified.
 	  </para>
         </listitem>
       </varlistentry>