None.
<p:pipeline name="pipeline" xmlns:p="http://www.w3.org/2007/03/xproc"> <p:output port="result"/> <p:load> <p:option name="href" value="pipeline.xproc"/> </p:load> </p:pipeline>
Port=result:
<p:pipeline xmlns:p="http://www.w3.org/2007/03/xproc" name="pipeline"> <p:output port="result"/> <p:load> <p:option value="pipeline.xproc" name="href"/> </p:load> </p:pipeline>