I saw another question that was about a (I assumed) a solid line that someone couldn't get rid of, and it turned out to be a border, etc. thing. This line is not acknowledged in the markings when I turn that on, it will not delete when I back space, and I cannot put my cursor on it--or near it. If I try, it goes into the text on the line above or below, depending on where I click.

Any idea what they are, and how to exorcise these demons from my innocent document?? Honestly, if I can't get help, I'm going to try burning sage....