HTML Cleanup use lowercase tags
Mostly this is just a pet peeve of mine, but I am a bit OCD about proper HTML markup. While uppercase html tags are acceptable and browsers will support it, it is not recommended.
http://www.w3schools.com/html/html_elements.asp
"W3Schools use lowercase tags because the World Wide Web Consortium (W3C) recommends lowercase in HTML 4, and demands lowercase tags in XHTML."
There's no way to override the automatic HTML cleanup and prevent it from block capitalizing all of my carefully prepared HTML, or get it to use lowercase tags.

With the 7.9 version release, we updated the code editor for editing HTML, CSS, and JavaScript. It supports lowercase as recommended by W3C.
We are not considering to change this behaviour but hope that with the new editor you will find the work with HTML easier.
More about a new code editor and 7.9 release https://gethelp.wildapricot.com/en/articles/1712-version-79-release