Multiple Doctypes in a single HTML Document

Question

If a HTML document has two doctypes, how will the doctypes affect the rendering of the page and which doctype would the browser pick? Is having two (or more) doctypes in a s

Answer 1

I believe the very first DOCTYPE is used by the browser and it's against the specification to have more than one in a document.

I think (not sure) that the only situation when multiple DOCTYPE-s may be valid is when using IE conditional comments. Browsers other than IE won't see those, of course.

I remember reading a blog entry (can't find it now, so I may be wrong in this) but some (most?) browsers even ignore the DOCTYPE if it's not the first thing they encounter. (This may have been a bug that got fixed since.)

Here's W3School's reference page about DOCTYPE:

http://www.w3schools.com/tags/tag_doctype.asp