It literally says in your excerpt "if there are more than six, list only the first three, followed by “et al.”" in the bibliography and says that notes without bibliography should follow the bibliography rules for et al

Et Al after three authors for works with more than 6 is implied by "as in the bibliography" in 13.23 -- you're welcome to ask CMOS about this, they do answer emails, but I promise you adunning's interpretation is what the Manual intends. It would make no sense to list more authors in notes than in a bibliography, not would the Manual establish a third different et al rule.

Adam, the scholarly editors group is equally divided on how to read that. I've submitted the question to the Chicago Q&A. I'll report back when and if they respond.

I've recently been using CMOS styles to write a paper, for which I use Zettlr for the Markdown and Zotero (via BetterBibTeX) to handle the referencing. One can then export the markdown file via Zettlr's internal pandoc to generate a new format; I generally send it to Word, since that is what is requested. Zettlr allows you to use the Zotero style files to do the rendering.

I recently swapped from 17 to 18 and noticed that with the change to 18 (and the reverse-engineering of 17 mentioned in these fora), that some of the forms of referencing have stopped working, whereas they worked perfectly in the previous version (of 17).

Specifically, the text used to indicate a chapter in a ref (i.e., "chap.") no longer appears to work, whereas "part", "figure", "Table", etc all seem to.

I find this to be so in most of the styles I've tried: notes; notes-bibliography; shortened-notes-bibliography; etc.

Example: the reference written in markdown in Zettlr as

[@kocs19io, chap. 7]

would when exported render, correctly, under the older CMOS 17 style as

(Kocs 2019, chap. 7)

However, under CMOS 18 and the revised 17, it now renders as

(Kocs 2019, 7).

Whereas, something like

[@matlock10si, chap. 1; @matlock24lbla, part III]

renders as

(Matlock 2010, 1; 2024, pt. III).

So, I am wondering: is the new CMOS deprecating the "chap." designator, or is there possibly a typo/bug in the style files that handle the "chapter" referencing?

I ask because using, e.g., Harvard Cite Them Right style, does insert the "chap." text in the Matlock citation above.

Anyone else notice this behaviour?

@dunning
Tried it in shortened-notes-bibliography and it worked!
I just commented out the line.

I have a lot of references for the paper, and I have noticed that while most are rendered in title capitalisation, as expected, a handful are done in sentence caps.

This is odd, because I store all refs in sentence caps, with the APA caveat of a capital after the colon in a compound title (i.e., main title and a subtitle; a throw back to olden times... I think CMOS does do this now). I've double-checked this, and when I change the citation of one ref which only has a title to another with a subtitle (i.e., a later paperback edition), the title caps work as expected.

However, the sentence caps also occurs for a ref which has a compound title, so is there perhaps another pandoc obscurity that causes this?

@jvoros I suspect that you're encountering the difference in pandoc versus citeproc-js (the citation processor in Zotero) in the interpretation of languages. Pandoc follows the CSL specification strictly, which states that the value of language should be an ISO 639-1 (= IETF) language tag, i.e. en for English. Zotero interprets this more loosely.

Thus, if you have an item with English or eng as the Language, it will be rendered in title case in Zotero but sentence case in pandoc. Changing the language to en will fix the problem.