There's more than four kinds; the main point should be that they need to be written with their particular purpose in mind. Here's some categories that apply jus

There's more than four kinds; the main point should be that they need to be written with their particular purpose in mind. Here's some categories that apply just to system operations: - Reference - Discussion - Planning - Tutorial/Educational - How-To - Process Template (many, many kinds) - Process Implementation - Q&A There are also attributes: Local/Global, Draft, Approved, Certified, Published, Restricted, Versioned, etc. There's the venue: Internal, Customer-facing, Regulatory, Quality Assurance, Development, Managerial, Executive, etc. Then there's the scope of the document: high-level, deep dive, navigation, etc. When you write documentation, you must know your audience, what they need your document for, whether your document gives them everything they need, whether it's clear & concise, and whether anyone can find it when they need to. They should know when it was written & by whom, what it was written for, who it applies to. It should provide references to everything someone needs to know to make use of the doc. And not only should the document be clear, it has to stylistically express detail and make the document easier to process.