In word, in several places, I see gray brackets - [ and ]. They look just
like standard 12 point square brackets in the text, except they are light
gray, like a header or footer, but they are not part of a header or footer.
I have no idea where the came from. I don't seem able to delete them - they
move with paragraph marks. I did delete one or more once (to my surprise),
but all I did was hit the delete key, that doesn't work now.

I assume those must signify something. Can anyone tell me what?

Thanks,
Colin