Simple
The world is complex enough as it is, so why should your code be. We make things simple, so we can all understand.
Meaningful
Every line should have meaning, why else would we write it down?
Adaptable
Code should be adaptable at any time. By keeping things simple and meaningful, adaptable code comes naturally.
Reliable
We want our code to be realiable in any circumstance, if it's not realiable, we didn't write it.
Tested
And to make all the above a reality, we ofcourse need our code to be tested, always, no exceptions!