Plain English
Documentation a non-technical reader can finish.
Most security and IT writing is hostile by accident. It uses jargon to signal expertise rather than to communicate, and the cost of that is paid by the people on the other end of the page — the bookkeeper, the school administrator, the founder reading it at eleven o'clock at night.
We write so the reader does not need a glossary. When a technical term is unavoidable, we explain it inline and only use it once. When something we sell sounds clever, we replace the word with what the thing actually does.