Backend

• based on Zend Coding Standards for PHP, PSR-1 and PSR-2
• Use Linux Linebreaks (\n)
• PHP code MUST NOT contain any character before the opening tag
• Uses spaces instead of tabs

Frontend

• LESS preprocessor is used whenever possible
• "wer floatet muss auch clearen"

Magento related

• All SQL updates (i.e. also CMS updates) are done via Magento setup scripts
• Individual settings are always done via its own configuration section in System > Configuration > Customer specific settings