Doesn't IE11 understand this sentence? _html/css_WEB-ITnose

Recognized by all except IE
This sentence is placed Why can I see it when I open it in IE11 in the body? ?

Reply to discussion (solution)

IE11 no longer supports conditional comments.
alert(navigator.userAgent) to see. It’s not msie anymore

Many of the original IE functions are no longer supported, please refer to
https://msdn.microsoft.com/en-us/library/ie/hh801214(v=vs. 85).aspx

This seems to be a very common technique

Not common at all