diff --git a/docs/filters.html b/docs/filters.html
index 425d189..58eb6fe 100644
--- a/docs/filters.html
+++ b/docs/filters.html
@@ -77,8 +77,18 @@ python. .xslt
involkes XSLT. .sed
and
perl or ruby or class/jar (java), aren't supported at the moment, but these
would be easy to add.
-
>
),
+then the output stream is
+teed; one branch flows
+through the specified filter and the output is planced into the named file; the
+other unmodified branch continues onto the next filter, if any.
+One use case for this function is to use
+xhtml2html to produce both an XHTML and
+an HTML output stream from one source.