TYPO3 Core

In class.tslib_pagegen.php, line 476 (T3 4.0 final) is the standard meta tag output for HTML:
<meta http-equiv="Content-Type" content="text/html; charset='.$theCharset.'" />'

With the new CSS Styled Content being much more semantic, and the availability of the (very useful) svo_mimetypesniffer extension, serving pages as real application/xhtml+xml (conditional on the browser accepting it) is a possibility, and indeed works well!

Although the HTTP header for the content-type can be overriden using config.additionalHeaders, there is no way to change the hardcoded text/html meta tag to application/xhtml+xml (or remove it entirely) short of disabling all header code and respecifying it with typoscript.

It would be nice to have a content-type option available in the CONFIG section that is substituted into the meta tag and the HTTP header cleanly, just as the charset is. If this was copied into the TSFE array as the charset is, making the changes would be a simple grep-and-replace job.

I'm happy to submit patches against CVS for this if you like.

(issue imported from #M3263)