is done by steps of 2 spaces  Don't put spaces after an opening parenthesis and before a closing one.  Use camelCase, not underscores, for variable, function and method names  Use underscores for option/argument/parameter names.  Braces always go on their own line.  Use lowercase PHP native typed constants: false, true and null.  When comparing a variable to a string, put the string first and use type testing when applicable Further references from: http://trac.symfony- project.org/wiki/HowToContributeToSymfony#CodingStand ards