The mysterious and pervasive "Rule Number 10"

Jason Mawdsley has written nicely about Coding Conventions: Make Them Agile ... These are simple rules to let your team deliver high-quality code as efficiently as possible.

Jason's agile coding convention is as follows:

1. Make your code look like other people's code.
2. Use the simplest design possible.
3. Don't re-invent the wheel.
4. Document your code.
5. Keep security in mind.
6. Work in increments.
7. Work in iterations.
8. Have your code reviewed.
9. Don't stay blocked.
10. (You'll have to read the article to find out)