internal pipelines (not reachable from outside, but with cocoon: pseudo protocol): <map:pipeline internal-only="true"/>
issues with paths, e.g. a showfile page where request param file specifies the file to show:
<map:match pattern="showfile">
<map:act type="request">
<map:parameter name="parameters" value="true"/>
<map:read src="{file}" mime-type="text/plain"/>
</map:act>
</map:match>