Examples of embed list sub-item styles are shown in the image below.
This document answers the question ... "How to I add a new template
for one of these?"
The answer: Basically an override - and this document indicates the
other content.ini settings to add too.
Not rocket science, but I find myself forgetting these things - and it
costs time to rediscover the which setting, where, why
information.
Hope this spares you some time for something good / fun / worthwhile.