Difference in display between HTML and XHTML

Question

I thought XHTML documents were supposed to be displayed with exactly the same standards compliance mode as \"strict\" HTML documents.

However, there is a difference

Answer 1

The removal of the starting newline is nothing to do with the rendering in HTML, and Dave Raggett's page is just a little imprecise and getting a little out of date. The removal of the starting newline is a property of the HTML parser.

In the in body tree construction phase the HTML5 spec for the text/html mime type says:

A start tag whose tag name is one of: "pre", "listing"

If the stack of open elements has a p element in button scope, then close a p element.

Insert an HTML element for the token.

If the next token is a "LF" (U+000A) character token, then ignore that token and move on to the next one. (Newlines at the start of pre blocks are ignored as an authoring convenience.)

Set the frameset-ok flag to "not ok".

An XML parser is simply not allowed to do this by the XML parsing rules, so XHTML does not drop that new line.