You may give it up right now, because you are not going to have your way on this. I know more about the Manual of Style than you, and I'm applying correctly. You have now been applying it incorrectly twice. Let me educate you:
The titles of the pages in question are List of stadiums by capacity and List of association football stadiums by capacity, respectively, which had the words "sports stadia" and "football stadiums" bolded, respectively. That's the clearly non-MOS-compliant version that was initially in place and which you reverted to, in apparent ignorance of the Manual of Style.
What's worse, since it is a separate violation of the manual of style: parts of those bolded phrases were wikilinked, as are the phrases in your ludicrous recent edits.
I recommend you cease editing those pages now, since you evidently don't have a firm grasp on our Manual of Style. I'm reverting, and suggest you ask more experienced editors than yourself at the Manual of Style talk page. Thank you. 85.197.52.156