I really like the efforts of GOV.UK to make their content clear, unambiguous and easy to understand. In particular, avoiding jargon unless it is needed. Of course, jargon has it's place when it addresses a technical or specialised audience.

From a different domain, here is an excellent blog post from 2019 on how to write clear health information for people with varying levels of literacy. (And no, it doesn't mean "dumbing down" your writing.)

Pee and poo and the language of health: https://digital.nhs.uk/blog/transformation-blog/2019/pee-and...