Attached is a patch for more rendering options for SHR.
The CITE, DFN, Q, and SMALL changes align with many browser agent stylesheets. The TIME exposes the underlying meaningful attributes. You might have a tag <time datetime="2021-08-26">Today</time> and exposing the datetime attribute (or title) helps clarify what is meant by "Today".
I'm excited to be submitting my first patch to Emacs core, and hope I've done my homework to get this right.