Order of frontmatter, bodymatter and backmatter not included in validation.

[oscarlcarlsson]

We just noticed that files with epub:type="frontmatter" is allowed after epub:type="bodymatter" in the validator.

Is it possible to check the names and order of the files in the validator? Shouldn't it always be the order frontmatter, bodymatter, backmatter?

[josteinaj]

Probably possible, but do you want it in all contexts? Maybe you want some frontmatter moved to the back of the book as part of ordering instructions, so that the book becomes more accessible? For instance you might want to move the colophon to the back of the book. Or maybe there's an index or a huge table of contents in the frontmatter. Should they become backmatter if you move them to the back as part of ordering instructions?

[josteinaj]

By the way, I think a change from 2015 to 2020 was that file naming rules were either removed or relaxed? In 2015 they are quite strict about epub:type in the filename, and numeric ordering. Adding, removing or moving files in the spine required a lot of file renaming and updating of refereces.