HTML recognition
Conditional annotation Method (IE10 and above does not support conditional annotations)
"Note" Two--and left bracket [cannot have spaces between them, otherwise invalid
[1] ie9-(<!--[if ie]><![ endif]-->)
<! DOCTYPE html>
[2] only single IE (<!--[if IE 6]><![ endif]-->)
<! DOCTYPE html>
[3] greater than GT | | Greater than or equal to GTE | | Less Than LT | | Less than or equal to LTE (<!--[if GTE IE 8]><![ endif]-->)
<! DOCTYPE html>
[4] Non-IE (IE10 and above can also be recognized), here more <-->, in IE as internal comments, and in non-IE browser will be closed before the comments (<!--[if! ie]><--><! [endif]-->)
<! DOCTYPE html>
CSS hack"1" attribute prefix method (ie supported only)
[1] IE6 (underline, Middle dash) (_color:blue;-color:blue;)
<! DOCTYPE html>
[2] IE7 and the following versions (*, +) (*color:blue;+color:blue;)
<! DOCTYPE html>
[3] IE10 and the following versions (\9) (color:blue\9;)
<! DOCTYPE html>
[4] IE8 and above (color:blue\0;)
<! DOCTYPE html>
[5] IE9, IE10 (\9\0) (color:blue\9\0;)
<! DOCTYPE html>
"2" selector prefix method
[1] IE6 (*html)
<! DOCTYPE html>
[2] IE7 (*+html)
<! DOCTYPE html>
[3] IE8 (@media)
<! DOCTYPE html>
[4] Ie9+ and other non-IE browsers (: root)
<! DOCTYPE html>
[5]firefox (X:-moz-any-link,)
<! DOCTYPE html>
[6]chrome, Safari, Opera (@media screen and (-webkit-min-device-pixel-ratio:0))
<! DOCTYPE html>
Common browser compatibility