The optional <Refs> element lists the links (references) from
the given document, for parent-child linking. Its text value is a
base64-encoded XML document with the following format when decoded:
<results xmlns:dt="urn:schemas-microsoft-com:datatypes">
<result>
<Url>http://www.example.com/dir/page.html</Url>
<Ref>http://www.example.com/dir/otherpage.html/</Ref>
</result>
...
</results>
Each <Url> should be the same as the <Url> in the above
<Item> block. The <Ref> is a single link from the page.
Only one <Ref> may be listed per <result>; additional
links should be sent with additional <result> elements.
The optional <Errors> element contains any errors to be logged
for the document. Note that this may be empty or not present if no
errors are to be logged. Its text value is a base64-encoded XML
document with the following format when decoded:
<results xmlns:dt="urn:schemas-microsoft-com:datatypes">
<result>
<Url>http://www.example.com/dir/page.html</Url>
<Reason>Document not found: 404 (Not Found)</Reason>
</result>
...
</results>
As with the <Refs> element, the <Url> must correspond
with the original <Item> <Url>, and multiple errors
must be listed in separate <result> elements.