Hide toolbar text-editing sub-row?

I’ve suddenly noticed a second row in the DT3 toolbar that I’ve never noticed before and that I want to get rid of—a small sub-row of greyed-out, apparently text-editing buttons, below the main buttons:

I’m not sure what they’re supposed to do or for what purpose they activate, and I can’t find anything in the “Customize Toolbar” area that seems to correlate to them, nor can I find any reference in the manual. Sorry if this is a dumb question with an obvious answer: What are they for and how can I make them go away?

Thank you.

See menu Format > Show/Hide Format Bar

Perfect, thanks!