Dreamweaver inserts an incomplete DOCTYPE in its default New Document. You can modify that. In Dreamweaver, open the default.html page located in Dreamweaver’s Application Folder > Configuration/DocumentTypes/NewDocuments. Look at Code View and find the DOCTYPE in line one. It says:
<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”>
Edit that line to add a URL before the closing greater than bracket, like this:
<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”
Save and close the page.
Congratulations! Every new default HTML page you create with Dreamweaver will now have a correct DOCTYPE.
This tip is from the Student edition of Macromedia Dreamweaver MX for Windows and Macintosh Visual Quickstart Guide that I’m in the process of writing.