How can I make emacs always close a sgml-tag (C-c-C-t)?
For example div, h2 tags work fine but p or li do not.
Basically I'm looking for a way of specifing that I'm always using xhtml when I insert a tag.
You need to turn on sgml-xml-mode:
When non-nil, tag insertion functions will be XML-compliant.
sgml-mode attempts to guess whether your buffer is in XHTML (and so turn on sgml-xml-mode automatically) by looking at the doctype. See the function sgml-xml-guess. It's expecting to find the string "XHTML" somewhere in the DTD name.
If you can't get sgml-xml-guess to work, then you could turn on sgml-xml-mode explicitly. Perhaps like this:
(add-hook 'html-mode-hook #'(lambda nil (setq sgml-xml-mode t)))
来源：https://stackoverflow.com/questions/4265314/make-emacs-always-close-html-tags