What doctype should I use

The doctypes on the website I'm currently working on is:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html lang="en">

I had to change it is that the new CSS dropdown menu would work.  This is an old site that is non-accessible compliant, and I want to change everything from tables to CSS.  This is what I changed it to:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<html lang="en">

Is that correct, or is there something better/newer I should be using?
smitty62Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Dave BaldwinFixer of ProblemsCommented:
Neither of those is quite right.  Here is the list of recommended DOCTYPES: http://www.w3.org/QA/2002/04/valid-dtd-list.html  You should use the one that matches your code.  It does actually make a difference.  The 'easiest' one to me is :

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<html>

If you use an XHTML DOCTYPE, you should make sure your code matches the XHTML rules.
0
smitty62Author Commented:
Thanks for the info.  I didn't know some of the DOCTYPES were going to be phased out.  I noticed that when changing asp pages from the old table style to CSS that dropdown CSS menus wouldn't work with the old DOCTYPE.  When I changed the DOCTYPE it altered the look of the CSS on the pages.  

What do you think about usine an include for DOCTYPEs, Meta Tages, Links, and CSS so that everything can be changed on all pages at once, or is that not a good idea?

Do you know of any good sites that can educate me about DOCTYPEs?
0
Ray PaseurCommented:
I use includes for DOCTYPEs, etc.  My framework has a "require_once()" for header, footer and sidebar code.  Mostly I use this doctype and HTML declaration:

<!DOCTYPE html>
<html dir="ltr" lang="en-US">

http://www.w3.org/QA/2002/04/valid-dtd-list.html
http://www.w3.org/TR/html401/struct/dirlang.html
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
smitty62Author Commented:
Thank you for your help.
0
Ray PaseurCommented:
Thanks for the points!  It's a great question. ~Ray
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Web Development

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.