I just added to the user guides Markdown implementation support for marking off warnings/tips specially (tip doesn't have CSS yet, but will soon once @Brock Whittaker does it): http://zulip.readthedocs.io/en/latest/README.html#supported-features
You can see an example of this at the top of the /help/ index page
Tip has CSS now
Last updated: Jul 19 2022 at 08:22 UTC