I would have thought Indesign automatically added them. I'm not proficient with CSS. Do you know where I can find out how to add them?
I copied this from my opf.
Code:
<package xmlns="http://www.idpf.org/2007/opf" xmlns:dc="http://purl.org/dc/elements/1.1/" unique-identifier="bookid" version="2.0">
<metadata>
<meta name="generator" content="Adobe InDesign"/>
<meta name="cover" content="frontcover.jpg"/>
<dc:title></dc:title>
<dc:creator></dc:creator>
<dc:subject></dc:subject>
<dc:description></dc:description>
<dc:publisher></dc:publisher>
<dc:date>2012-04-09</dc:date>
<dc:source></dc:source>
<dc:relation></dc:relation>
<dc:coverage></dc:coverage>
<dc:rights></dc:rights>
<dc:language>en-GB</dc:language>
<dc:identifier id="bookid"></dc:identifier>
</metadata>
<manifest>