Why must I define a browser cap in web.config

I g开发者_开发知识库ot this section in my web.config:

<browserCaps>
  <case match="^Mozilla/(?'version'(?'major'\d+)(?'minor'\.\d+)(?'letters'\w*)).*">
    <case match="^[5-9]\." with="${version}">tagwriter=System.Web.UI.HtmlTextWriter</case>
  </case>
</browserCaps>

It must come from an older project from witch we start this one. We started this one about 4 years ago.

Anyways, seeing that, it seems to say "If the user agent is Mozilla, use a different HtmlTextWriter".

I suppose a different HtmlTextWriter means different results in the markups for the same server code. If it is so, it is in my opinion very nasty.

Can anyone confirm if it is the case or not? Maybe I misunderstood the whole thing ?

Take a look at this: http://msdn.microsoft.com/en-us/library/sk9az15a.aspx

Looks like this was deprecated when .net 2 came out (in 2005).