beginning or end of the chain, remove a filter, or clear the chain.</dd>
</dl>
</section>
+<section id="upgrade"><title>Upgrading from HTTPD 2.2 Configuration</title>
+ <p>The <directive module="mod_filter">FilterProvider</directive>
+ directive has changed from HTTPD 2.2: the <var>match</var> and
+ <var>dispatch</var> arguments are replaced with a single but
+ more versatile <var>expression</var>. In general, you can convert
+ a match/dispatch pair to the two sides of an expression, using
+ something like:</p>
+ <example>"dispatch = match"</example>
+ <p>The Request headers, Response headers and Environment variables
+ are now interpreted from syntax <var>$req{foo}</var>,
+ <var>$resp{foo}</var> and <var>$env{foo}</var> respectively.
+ The variables <var>$handler</var> and <var>$Content-Type</var>
+ are also supported.</p>
+ <p>Note that the match no longer supports integer comparisons
+ or substring matches. The latter can be replaced by regular
+ expression matches.</p>
+</section>
<section id="examples"><title>Examples</title>
<dl>