The 10 Commandments of Programming...

Question

...or programming related activities

There's a certain text (The Bible) which suggests that there were, at least at one time, a list of 10 rules (The 10 Commandments) that if followed you would be considered, well, "good".

If such a list existed for programming, what would it be? I'm thinking in terms of languages (or language types) that you must know, or best practices, etc.

My apologies if this question is inappropriate or too vague.

Answer 1

Write your code as if the person who will maintain it is a psychopath who knows where you live.

Answer 2

Thou shalt not repeat thyself.