I know this sounds unnatural from your perspective:

When a manuscript is completed and edited, I format it for the print version, which has front and back matter all formatted differently from the interior, with no headers, usually different fonts, and a required number/specific position of blank pages.

For the interior, all chapters must start on the right. I have an image to accompany each chapter which is placed on the left page, opposite the new chapter. Chapter numbers and names are stylized, designer fonts. If a chapter ends on the left page the right page is left blank. Blank pages, 1st pg. of a chap., and image pages don't have headers displaying the page number.

All other pages have headers with the author name and pg. # on the left, right justified; and book name and pg. # on right, left justified. Then there are images separating sections within chapters and some other, minor formatting standards depending on the publisher and/or printer. I use right/left section breaks to suppress headers and to create blank pages.

When the print version is perfect and uploaded, then I strip out the blank pages and headers to create the ebook version, but leave all the section breaks, etc., basically because there's no need to remove or change them. (To save print cost and reduce shipping weight, we often vertically adjust line spacing--but that wasn't necessary in this book except for the Table of Contents.)

I do use the ruler to set indents throughout, but where an indent is unwanted it's easier to do a shift + return than to change the ruler back and forth.

This is the first phantom line instance where I couldn't find a cause.

TMI?