Hi,
Do you want to use it as a repository or product? As a repository I'm using...
<add-on>
<add_on_products config:type="list">
<listentry>
<media_url>relurl://...</media_url>
<product>product-name</product>
<alias>alias-name</alias>
<priority config:type="integer">40</priority>
<product_dir>/</product_dir>
<name>the name</name>
<ask_on_error config:type="boolean">false</ask_on_error>
<signature-handling>
<accept_unsigned_file config:type="boolean">true</accept_unsigned_file>
<accept_verification_failed config:type="boolean">true</accept_verification_failed>
</signature-handling>
</listentry>