addremove: do not deprecate.
command is too useful to drop.
is also best place to try autodetect of rename/copy by content similarity.
<item>
<title>#tag|escape#</title>
<link>#url#?cs=#node|short#</link>
<description><![CDATA[#tag|strip|escape|addbreaks#]]></description>
<pubDate>#date|rfc822date#</pubDate>
</item>