1. Linear reading: define things before talking about them.

2. Make documentation explicit, not implicit: no acronyms or assuming context.

3. No marketing or self-promotion: your code is not fast, efficient, reliable, convenient or secure because you say so.

4. No ego: nobody has time to read about you or a story from your life. Keep that to your blog.

5. No humor: if it's 3 AM and you are debugging a problem, and you are being forced to read lame jokes to understand what some code does, you are going to get frustrated as hell.

6. Punctuation, grammar, orthography.

7. No aggression: Nobody has time to read rants as they're trying to work on code.

8. Prefer simple English, leave local idioms and slang aside.

9. Conciseness.