All I know is I see this:
Code:
<metadata xmlns:calibre="http://calibre.kovidgoyal.net/2009/metadata" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:opf="http://www.idpf.org/2007/opf" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<dc:publisher>Vincent Trigili</dc:publisher>
<dc:language>en</dc:language>
<dc:creator opf:file-as="Trigili, Vincent" opf:role="aut">Vincent Trigili</dc:creator>
<dc:title>The First Quartet</dc:title>
<meta content="cover" name="cover" />
<dc:date>2013-04-25T04:00:00+00:00</dc:date>
<dc:identifier id="uuid_id" opf:scheme="uuid">160df120-4549-4348-8680-b49d2d1fa6f0</dc:identifier>
<dc:identifier opf:scheme="calibre">160df120-4549-4348-8680-b49d2d1fa6f0</dc:identifier>
<dc:date opf:event="modification">2013-04-28</dc:date>
</metadata>
And other stuff like it in the EPUB that I did not put there, and Calibre did. So I disagree that Calibre does not add meta data to the files. Publisher, language, etc. I ONLY set that in Calibre.