This is It

This is what happens when an author of a manual doesn't look at the work they are doing or, alternatively, allows MS Word to not do what is expected.

I happened upon this PDF, which was published on 1/11/2018:

Notice how the "Introduction to Test Security" section is called 2.1 and yet, in the very next section, "Introduction to Before Testing" isn't numbered. I question it was intentionally left un-numbered because, it's obvious because of where the headings line up in the TOC, which is based upon bookmarks which, I'm guessing is automagically generated by headings, that it has the same heading style applied. Or it did, at some point. It's quirky.

If I were the technical writer in charge of this PDF, I would edit the Word document that generated the PDF and re-apply Heading 2 to the "Introduction to Before Testing"...