First, I must admit I don't know much abut W3 (actually almost no knowledge on the subject), and am not even sure what its purpose or use is but do know it's important.
We recently had some misc programs or toolbars which did not work right. After contacting support they said it was due to the W3 lines (or lack thereof) at the very top of the index page. Depending on which program had the issue it seemed to revolve around one of the 3 W3.org lines listed below.
Instead of trying to figure out which is best to use for all sites, including sites without issues and new sites, we are wondering if we can use all three lines and would that necessarily cause any issues?
Maybe someone could suggest a new W3 code line which is better than the 3 lines below (or somehow blends all of them together), and could in-effect cover all possible scenarios? The top 3 lines which are all currently installed on our last few new sites are below. Thanks for your help.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"; >
<html xmlns="http://www.w3.org/1999/xhtml">