The sad fact is there isn't one. There should be, it is important. The reason there isn't is because I can find no single compelling guide to adopt so the options are:

• Pick one at random, reformat the codebase.
• Write a new one based on the de-facto style that's already there.

Neither option greatly appeals so for now the rule is: try to be consistent with what is already there, even if you don't like it much. Consistency is better than nothing.

At some point (soon) we'll have to take this issue seriously. If you have suggestions for style guides that you feel are particularly good, or any suggestions on this topic please post the qpid-dev list to get the ball rolling again.