Meta tell IE browser compatibility mode

In the head of the HTML, the following is written, excerpt from http://www.xingzai.org/html-note/meta-tag-usage-order.html:

2. <!--x-ua-compatible (browser compatibility mode)
4. Only for ie8+ to be effective
6. Tell the browser what version of IE compatibility mode to display the Web page
8. <meta http-equiv= "x-ua-compatible" content= "ie=5" >
10. <meta http-equiv= "x-ua-compatible" content= "ie=7" >
12. <meta http-equiv= "x-ua-compatible" content= "ie=8" >
14. <meta http-equiv= "x-ua-compatible" content= "Ie=edge" >
16. The last line is always to display the Web page in the latest IE version mode.
18. Plus emulate mode
20. <meta http-equiv= "x-ua-compatible" content= "Ie=emulateie7" >
22. <meta http-equiv= "x-ua-compatible" content= "IE=EMULATEIE8" >
24. Emulate mode is more important after <! Doctype>
26. (The attentive person will notice that the Compatible View button does not appear when using IE9 to access pages with x-ua-compatible)
28. -
30. <meta http-equiv="x-ua-compatible" content="Ie=emulateie8" />

Http://cssor.com/meta-ie-x-ua-compatible.html

Meta tell IE browser compatibility mode