Breaking: #97927 - Removed TypoScript option config.doctypeSwitch
See forge#97927
Description
Previous TYPO3 versions allowed to set
config.
via TypoScript.
If this option was set, the order of <?xml...> and <!DOCTYPE...> during the rendering of a Frontend page was reversed. This was needed in the past for Internet Explorer to be standards-compliant with XHTML. Otherwise IE's "Quirks Mode" was used.
Nowadays, usages for both Internet Explorer (which is not supported anymore) and XHTML have been low, which is why the option is now removed from TYPO3 Core.
Impact
Setting the option
config.
has no effect anymore, the
XML declaration and doctype statement are kept as is.
Affected installations
TYPO3 installations with old templates having this TypoScript option set.
Migration
It is recommended to avoid using this functionality, and to switch to HTML5.