I wrote, built, and published a webbook on my personal website. To disambiguate, the word "webbook" refers to a book whose content is directly readable on a website in HTML format, not an epub to download or a PDF.
This webbook is split across multiple webpages. Each webpage is a chapter.
I am currently working on the meta-aspects required by the medium: performance, SEO, usability, accessibility, etc. Which leads me to the structured data question.
So my question is: What can I declare as structured data for a webbook?
I have found schema.org's "CreativeWork", which is kind of matching a webbook yet a little vague, and its subtype "Chapter". I have also found "WebContent", but it's vague as well.
"Book" seems limited to physical books. And it looks like it is not supported by any major company (or you must be big enough to appear on Google's apps). "Article" seemed to fit at first, but the way Google presents the data makes it—in my opinion—unfit for the task (chapters appearing as articles in a news feed). As a side note, I also checked Bing's Webmaster Tools help about its supported types, but even fewer options are listed compared to Google.
Maybe I should just give up on trying to properly declare my content because I would get no benefit from that structured data?
If you want to see the webbook I'm talking about, you can access it here (it's in French but the content is not what matters for my issue): https://nemulumen.lightnovel.online/tnbs1/
Book is the right type here.
It’s not limited to physical/paper-based works, as its definition just says "A book", without mentioning the format. There’s also the bookFormat property, for which values like EBook and AudiobookFormat are defined, which wouldn’t make sense if the Book type were only intended for paper-based books.
To convey that the Book is available as HTML, you can use the encoding property (where the Book would represent the work, and the MediaObject would represent the HTML encoding of this work), or the encodingFormat property.
To connect the Book with each Chapter, you can use the hasPart/isPartOf property.