[DiapDealer]

Originally Posted by Doitsu

IMHO, this is a non-issue.

• That particular metadata entry is only used by Calibre and Calibre-adjacent software.
• The Calibre metadata parser doesn't require any particular attribute order.

Spoiler:

<metadata xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:opf="http://www.idpf.org/2007/opf">
	<dc:creator opf:file-as="Doe, John">John Doe</dc:creator>
	<dc:language>en</dc:language>
	<dc:title>Nitpicking for dummies</dc:title>
	<meta content="Nitpicking for dummies" name="calibre:title_sort"/>
	<meta content="The art of nitpicking" name="calibre:series"/>
	<meta content="1" name="calibre:series_index"/>
	<dc:date opf:event="modification" xmlns:opf="http://www.idpf.org/2007/opf">2023-01-27</dc:date>
	<dc:identifier id="BookId" opf:scheme="UUID">urn:uuid:d420bc81-9545-4313-b490-8bc75822cda2</dc:identifier>
</metadata>

I'd normally agree. But the reason we changed Sigil to maintain attribute order was so that doing diffs and checkpoints would reveal accurate -- useful -- changes that had been made to an epub.

So we'd probably be looking at this even if it had nothing to do with calibre series metadata. The fact that it affects some broken reading systems is secondary here. Even though metadata order should be irrelevant, we made a decision that Sigil should maintain attribute order as entered. This runs afoul of that.