For Dreamweaver 3 and above. ExtensionsManager necessary.
Download it first!!
Don't you just hate that. You just made a great looking page in Dreamweaver and tried to validate it on the W3C site and it complains your HTML isn't valid because the Doctype is missing. Here's the solution: a simple object which presents you with a pop-up list from which you can choose a doctype to insert in your document in the correct place and syntax.
Current version 2.1.1: XHTML 1.1 Doctype. Changed HTML 401 DTD references to finalized versions instead of the working drafts (they are identical but the string generated is somewhat easier to read and takes up less code, there is no need to change your existing documents).
Download Macintosh version
Download PC version
Access from the Commands menu. Cross-platform, 4k
Note 1: Dreamweaver MX now includes a doctype when you create a new document. As such this extension is of not much use in that version.
Back to Extensions
Note 2: When you give a document an XHTML doctype you will have to manually edit the opening <html> tag to the following: