PDF - How to exclude Books topics from TOC

Re: Try setting p-pdf-toc-level3 to display: none and see what happens. 

I've tried this but it doesn't work. will keep investigting.

In Classic, for Word/PDF, there's an option under Advanced to limit TOC depth. I can't see a corresponding setting in the preset for either PDF or Word.

I looked at the pdf.css in a fresh topic, and I wonder if the p.pdf-toc-level1 to 6 styles might affect the display.

Try setting p-pdf-toc-level3 to display: none and see what happens. (Your screenshot seems to indicate you want to exclude the third level of the toc, hence my suggestion. If it's a different level, change that level instead.)

Note I haven't tried this myself, but I feel the theory is sound.

Without setting up a test, I don't think that can be done. The topic headings are what creates the PDF TOC so if your topic has a heading style, that heading will be in the PDF TOC.

If it is text that looks like a heading but isn't, it should still appear in the output as long as it is in the TOC used for generating. 

sorry, i didnt express myself clearly. 

In the Alerts book, I have several topics, all H1. that's fine.

I also have two books in the toc, Alert Types and Alert Status. 

I DON'T want these to appear in the PDF TOC, 

I want the content to appear, but not listed in the TOC. 

This is the PDF.

You can see that it includes all the items listed in these books, a mix of H1 and H2.

How do I EXCLUDE these from the TOC?

I'm not sure if for the book going to its Properties and selecting Hide In Output will do what you want.

If not then it might be easier to copy the TOC and then remove the books so that only topics are listed. You can then hide any of those as required. Select the copy TOC when you generate PDFs.