This poem provides more interesting meat for the name controversy:

<bibl>
<title type="incipit">And now my pen alas wyth wyche I wryte</title> which is Book <num type="Roman" value="4">IV</num>, lines <num>13-14</num> from <title type="source">Troylus and Creseyde</title>, also known as <title type="incipit_alternate">The double sorwe of Troilus to tellen</title>, by <name>Geoffrey Chaucer</name>, which is based on <title>Rime <num>132</num> <title>If love be not o Lord what fele I so</title> ( <title><foreign xml:lang="ita">S'amor non è</foreign></title>)</title>, also known as <title type="alternate">Troilus' song</title>, which appears in <title type="main">Troylus and Creseyde</title> as Book <num>I</num>, lines <num>400-420</num> by <name type="personal"><reg>Petrarch, 1304-1374</reg></name>.</bibl>

Here, Geoffrey Chaucer has no <reg> tag at all, and it's not clear whether he, or Petrarch, ought to be listed as the author for this piece.

Karin suggests that authors are not so important in this document, and so the TOC need not list them. That would make my life easier, of course, but I think one way or another readers are going to want to be able to find texts based on authorship, no matter how disputed or uncertain, so even if they don't appear in the TOC, we'll have to deal with this problem.