As the question states basically. If you have X-UA-Compatible in both your HTTP headers and a meta tag on your document, and they conflict, which one gets respected by IE?
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试):
问题:
回答1:
TL;DR: The meta tag wins
I found the following (updated) flowchart here (link is broken) and associated blog post that provides an explanation of how IE9 determines document mode:
{var%20f='http://v.t.sina.com.cn/share/share.php?appkey=1515056452',u=z||d.location,p=['&url=',e(u),'&title=',e(t||d.title),'&source=',e(r),'&sourceUrl=',e(l),'&content=',c||'gb2312','&pic=',e(p||'')].join('');function%20a(){if(!window.open([f,p].join(''),'mb',['toolbar=0,status=0,resizable=1,width=440,height=430,left=',(s.width-440)/2,',top=',(s.height-430)/2].join('')))u.href=[f,p].join('');};if(/Firefox/.test(navigator.userAgent))setTimeout(a,0);else%20a();})(screen,document,encodeURIComponent,'','','https://i.stack.imgur.com/DmAC0.png', '推荐 疯言疯语 的文章《Which X-UA-Compatible takes precedence? Http-heade》','https://www.manongdao.com/article-94108.html','页面编码gb2312|utf-8默认gb2312'));){kind=link}