Trouble publishing to Netscape from MX Pro

Does anyone know what the purpose of this code is?

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “”>

Flash MX Pro automatically creates it at the top of the HTML page when I publish HTML for Flash Player 7, AS 2.0. And what I’ve found is that code, if not removed, does not allow your swfs to be viewed properly in Netscape.

I prefer to just remove it but was wondering what other browser problems I may run into.