As a general rule the coding standard to follow is the coding style of the module owner.

So no I will not list long rules to follow, the numerous source code should give you a pretty good idea of the coding standard in use :).

Here some general convention:

• use 4 SPACES, no TAB
• class/constructor always start with upper case ( HelloClass )
• method/property always start with lower case ( helloMethod )
• private always start with 1 underscore ( _ )
• internal always start with 2 underscores ( __ )
• protected are named as public (because we can reuse it in inheritance)
• public and protected are always documented with NaturalDocs style
• use Subversion, always log a message when you commit
• use unit tests consistently
• provide meaningfull names (Using Good Naming To Detect Bad Code)
• don't over comment the code, for more details use the wiki
• avoid the code smells
• no duplicate code, see once and only once
• no too long methods
• no class/constructor with more than one responsibility
• etc.
• no pre-processor

In brief, be code-centric, keep it simple and keep it readable :).