comparing https://github.com/symfony-cmf/standard-edition/blob/master/app/config/config.yml#L52-L58 with https://github.com/symfony-cmf/cmf-sandbox/blob/master/app/config/config.yml#L56-L63 i think this is a bug of the standard edition to comment out those options. it would not hurt to provide them with empty values as we do with the sandbox, and much less confusing. i propose to fix the standard edition instead. tampering with config.yml for this is more confusing than anything else.