according to the rules (de acordo com as regras; de acordo com as leis; “como manda o figurino”)
“I was surprised when I heard about that company’s shady deals, as they had always done everything by the book”, Patrick told his partner.
“Fiquei surpreso quando ouvi falar dos negócios escusos daquela empresa, pois eles sempre tinham feito tudo de acordo com a lei”, disse Patrick ao sócio.
Dave has always been regarded as a serious and honest businessman and has always done everything by the book.
Dave sempre foi considerado um homem de negócios sério e honesto e sempre fez tudo de acordo com a lei.