This is a question that's been brewing for a long time in my head
The wiki for sound_warning says "this meta tag is for video and Flash posts containing obscenely loud sound at any point", yet it seems that in practice it's basically interchangeable with just sound on the site. Pretty much every single video I've posted on the site ends up getting tagged with sound_warning, and the same happens with many random submissions containing otherwise surprisingly tame audio levels
Are these just all mistags, or is the wiki for the tag just overselling how loud sounds must be to qualify for it?