Coding Standard

XP teams all write code in the same style. This makes pairing easier and supports collective ownership. The standard need not be comprehensive, nor need it even be written. You just want everyone writing code that looks the same way. (Note that coding standard interacts with metaphor, which follows.)

Is a Coding Standard Essential?

You can probably live without a formal written standard. With good will, you can even let the team evolve to a common style. But I do mean good will: If everyone goes off in their own direction, or if people are inflexible about their favorite indenting style, your code will look chaotic and will be harder to understand. It's easy to pick a coding standard, and I recommend that you do so.